Tag: Wasps

Categories
native plants Pollinator gardening

Green-Eyed Starbursts

Cutleaf Coneflower (Rudbeckia laciniata)

Rising above the garden, bright yellow, green-coned flowers light up the garden.  Magnets for bees of all sizes, Cutleaf Coneflowers (Rudbeckia laciniata) invite insects for pollen and nectar rewards.  Chosen as 1995 North Carolina Wildflower of the Year, its blooms brighten the garden from mid-summer to early fall.1,11

Cutleaf Coneflower grows over a wide climate range, thriving in Zones 3 through 9.  It can reach 10 feet in height although it often only grows to 3 feet.  Individual plants spread from 1.5 to 3 feet.1,10,12  
 
The best growing conditions include full sun to part shade.  It likes moist conditions and slightly acidic, fertile loam or silt-loam.  In fact, Rudbeckia laciniata is happy in poorly drained, shaded areas with occasional flooding.  If it’s too sunny and dry, the leaves droop and wither.1,10,12

Cutleaf Coneflower lives in a variety of moist natural habitats.  These include bottomland forests, woodland borders, moist meadows in wooded areas, sloughs in moist areas, moist thickets, low areas along rivers, partially shaded riverbanks, alluvial thickets, calcareous seeps, low, rich woods, and margins of poorly drained fields and pastures.1
 
When this Coneflower is too happy, it spreads aggressively.  The roots are fibrous and rhizomatous, and it can form large clonal colonies.  Control this with division.  Encourage rebloom by cutting spent summer flowers.1,10,12

Despite what I’ve said so far, I grow this plant in a raised bed with no irrigation.  Why?  It grows happily there!  It does tolerate some drying out.  Yes, it loses a few leaves but it’s much easier to control those rhizomatous roots.  In addition, it can withstand hot, humid summers.12
 
Rudbeckia laciniata’s foliage varies in shape.  Leaves have 3 to 7 lobes with the number increasing toward the bottom of the stalk.  At the plant’s base, some leaves may even be pinnate(with separate leaflets).  The flower stalks have smaller, oval or lanceolate foliage.1
 
Leaves grow alternate on the stem and tend to droop.  They can reach 12 inches long and 12 inches across.  The edges range from smooth to coarsely toothed.  The upper surface is dark green and hairless to slightly hairy.  The lower surface is pale to medium green and smooth to lightly hairy.1
 
Sunny yellow flowers top this Coneflower.  The flowers sit atop an upper stem or are part of a group of flower stalks which often open at different times.  Each flower stalk can be 1 to 2 feet long.1,10  


The daisy-like flowerheads open to 2 to 4 inches and have a rounded cone.  6 to 12 drooping petals (ray florets) frame the center.  The cone starts as a bright green and then turns a greenish yellow as the disc florets open.  Disc florets form tubular corollas producing a pin cushion like appearance.  Seeds form from these florets.1

Cutleaf Coneflower blooms form mid-summer to early fall.  Flowering period last from 1 to 2 month.  The time is extended by buds opening at different times.1,10,12
 
Rudbeckia is one of the top 20 Keystone plants for EcoRegion 8.  The Commission for Environmental Cooperation created theses EcoRegions.  This commission is a multinational group including Canada, the United States and Mexico.  EcoRegion 8 includes the eastern part of the United States through Wisconsin and Illinois and South to the border.  The very tip of Florida and the Gulf coast of Texas are excluded.13

Keystone plants support specialist bees and/or are larval hosts for butterflies, moths and skippers.  Cutleaf coneflower appears on both lists.  It feeds 29 specialist bees and 20 different types of butterfly/moth/skipper larva.5
 
Rudbeckia laciniata attracts long- and short-tongued bees.  It’s been designated of Special Value to Native Bees and Special Value to Honey Bees by the Xerces Society for Invertebrate Conservation.  Bee visitors include bumblebees (Bombus),

honeybees (Apis mellifera),

large carpenter bees (Xylocopa spp.),

Halictid bees (Halictus spp.),

Green Sweat Bees (Agapostemon spp.) and

small carpenter bees (Ceratina spp.)1,2,12


Agapostemon spp., a green metallic sweat bee, are charming.  With an iridescent green thorax, these bees can have a green abdomen or a striped black and white abdomen.  They are generalists but enjoy flowers from the Asteraceae family.  These bees are active from mid-spring to mid-fall.  With fewer blooms available in spring, overwintering females often visit a greater variety of flowers then.3

These green sweat bees are solitary or communal.  When communal, the nests are spread out.  They nest in the ground with 1 or 2 generations per year in the Midwest, Great Lakes and Northeast.3
 
The offspring sex ratio changes depending on the number of generations.  With 2 generations, mated females emerge in mid-spring.  This group lay mostly female eggs.3  

Of the first-generation brood, some won’t mate at all.  These lay unfertilized (male) eggs.  Mated females lay a balanced proportion of males and females.  When these young emerge, the second-generation brood forage until mid-fall, mate, and then fertilized females spend the winter underground.3

When there’s one generation, the male to female ratio is much closer.  They appear in early summer.  These bees live throughout the growing season and mate in mid-fall.  Then fertilized females spend the winter underground.3

Flies also visit Cutleaf Coneflower.  Bee flies (Family:  Bombyliidae), Hoverflies (Rhingia) and Syrphid flies (Eristalis spp.) harvest resources.2

Predatory wasps also gather nectar from Rudbeckia laciniata.  These include thread-waisted wasps, sand wasps, mason wasps and bee wolves.1,2
 
Eremnophila aureonotata or Gold-marked Thread-waisted Wasp is the only Eremnophila in North America.  An elegant wasp, it has fine gold or silver hairs on its head and thorax.  There are also white or silver spots on the thorax.4

Gold-marked Thread-waisted Wasp nests in compacted sandy-loam or loam soil.  The nesting area is vegetated, concealed and located near a wooded area.  The wasp digs a hole 2 inches deep for its nest.  When leaving, she covers the entrance with fragments of plants.4 

Eremnophila aureonotata hunts caterpillars to supply her nests.  She searches on plant leaves for larva.  Once captured, the wasp paralyzes it by stinging.  She carries the caterpillar back to the nest and sets it outside.4  
 
The wasp removes the vegetation from the entrance and flies it away. Then she drags the caterpillar into her burrow and lays one egg on it.   The wasp closes the entrance with soil and pieces of plants.  She tamps the entrance closed with her head.4

Gold-marked Thread-waisted Wasps act as beneficial insect by hunting caterpillars.  They harvest noctuid moths (Noctuidae), prominent moths (Notodontidae), and sphinx moths (Sphingidae).  Noctuid moths are a large and varied group.  Cutworms, armyworms, corn earworms, and iris borers all belong in this group.  Cutworms eat the seedling off at soil level and pull it underground to eat.  Armyworms eat turf grass and cereal crops like millet and rice.4,7,8,9
 
The sphinx moths (Sphingidae) family include tomato and tobacco hornworms, pink-spotted hawk moth, and Pandora, Achemon, and Virginia Creeper Sphinx moth.  The tomato and tobacco hornworm larva eat tomato, potato, pepper, eggplant, tobacco and other nightshade family plants.  Pink-spotted hawk moth caterpillars consume sweet potato vines.  Pandora, Achemon, and Virginia creeper sphinx moth caterpillars are pests in vineyards.  Eremnophila aureonotata gathers all these larvae.8
 
Butterflies, Moths and Skippers nectar from Rudbeckia’s flower while some use it as a larval host.  Common Eupithecia (Eupithecia miserulata), Wavy-Lined Emerald Moth (Synchlora aerata), Southern Emerald Moth (Synchlora frondaria) and Silvery Checkerspot Butterfly (Chlosyne nycleis) all use this Coneflower to feed their young.1,2

I hope you enjoyed this exploration of Cutleaf Coneflower and the insects it supports.  An easily grown plant, Rudbeckia laciniata makes a wonderful addition to the moist garden.  Enjoy dreaming about next year’s garden!
 
Happy Gardening,
Mary Quinlan
 
BIBLIOGRAPHY:

  1. “Cutleaf Coneflower (Rudbeckia Laciniata).” n.d. Accessed September 29, 2025. https://www.illinoiswildflowers.info/savanna/plants/cl_coneflower.htm.

2. Holm, Heather. 2014. Pollinators of Native Plants:  Attract, Observe and Identify Pollinators and Beneficial Insects with Native Plants. Pollination Press LLC

3. Holm, Heather. 2017. Bees:  An Identification and Native Plant Forage Guide. Pollination Press LLC.

4. Holm, Heather. 2021. Wasps:  Their Biology, Diversity, and Role as Beneficial Insects and Pollinators of Native Plants. Pollination Press LLC.

5. Keystone Native Plants – Eastern Temperate Forests – Ecoregion 8. n.d.  Accessed September 29, 2025.  https://www.nwf.org/-/media/Documents/PDFs/Garden-for-Wildlife/Keystone-Plants/NWF-GFW-keystone-plant-list-ecoregion-8-eastern-temperate-forests.pdf.

6. Native Plants for Pollinators & Beneficial Insects: Midwest. Accessed September 29, 2025. 2023 The Xerces Society for Invertebrate Conservation.  https://xerces.org/sites/default/files/publications/22-025_01_NPPBI—Midwest_web.pdf.

7. Missouri Department of Conservation. n.d. “Noctuid Moths.” Accessed October 1, 2025. https://mdc.mo.gov/discover-nature/field-guide/noctuid-moths.

8. Missouri Department of Conservation. n.d. “Sphinx Moths (Hawk Moths).” Accessed October 1, 2025. https://mdc.mo.gov/discover-nature/field-guide/sphinx-moths-hawk-moths.

9 “Noctuidae – Wikipedia.” n.d. Accessed October 1, 2025. https://en.wikipedia.org/wiki/Noctuidae.

10. “Rudbeckia Laciniata – Plant Finder.” n.d. Accessed September 29, 2025. https://www.missouribotanicalgarden.org/plantfinder/PlantFinderDetails.aspx?taxonid=277226.

11. “Rudbeckia Laciniata (Cutleaf Coneflower, Green-Head Coneflower, Green Headed Coneflower, Tall Coneflower, Wild Goldenglow) | North Carolina Extension Gardener Plant Toolbox.” n.d. Accessed September 29, 2025. https://plants.ces.ncsu.edu/plants/rudbeckia-laciniata/.

12. “Rudbeckia Laciniata (Green-Headed Coneflower) | Native Plants of North America.” n.d. Accessed September 29, 2025. https://www.wildflower.org/plants/result.php?id_plant=rula3.

13. US EPA, ORD. 2015. “Ecoregions of North America.” Data and Tools. December 13, 2024. https://www.epa.gov/eco-research/ecoregions-north-america.
 

Categories
Pollinator gardening

Plan for a Wet Day:

The Rain Garden

Why talk about rain gardens?  Different from my usual blogs, rain gardens are a wonderful application for native plants.  In my yard, there are several wet and soggy areas especially in spring.  I’ve installed several rain gardens since 2020. They move the water through quickly and make the space usable.  As a bonus, these gardens are beautiful and filled with life-butterflies, bees, other pollinators and birds.

Why do we need a special garden?  Before people, rain on land fell mostly over forests and grasslands. These ecosystems slowed it down before and after it hit the soil surface.  Instead of running rapidly into lakes, streams, and other bodies of water, it was absorbed into the soil.  The soil system filtered and cleaned it.  Then, the water returned to underground aquifers.  


Now, many areas are impacted by humans.  Vehicle and foot traffic compacts the soil and hard rains runs off it.  Rainwater falls on hard surfaces such as roofs, pavement, even lawns.  As it runs across these, the water picks up dirt, oil, gas, other auto fluids and lawn fertilizers and pesticides.  It also gets warm.  

Once it enters the storm sewer it flows rapidly into rivers and lakes.  Once there, silt clogs creatures gills, fertilizers promote algae growth and pesticides, and other chemicals cause many problems.


But the good news!  Rain gardens can help.  Rain garden are specially constructed gardens that hold water for short periods of time (usually less than 24 hours and not more than 48 hours).  While it’s held, natural processes slow its path.


Thick vegetation catches and holds it.  In the soil, plant roots absorbed some of the water.  More water is held in small spaces in the soil.  These spaces are created by plant roots, fungi and other microorganisms, soil-dwelling animals and insects.  


Some chemicals adsorb to soil particles.  Certain soil microbes digest chemicals like those in gasoline converting them it carbon dioxide and water.  Through these pathways, the rainwater slowly works its way to the groundwater aquifer.  It arrives cleaner than it fell.


Designing and building a rain garden involves a detailed process.  Some features are specified by states.  Detailed plans are beyond this blog, but I’ll provide references for free resources.  


If you have questions, especially regarding garden placement near drinking water wells and septic fields, I suggest contacting local water quality officials for information.  In Michigan, this would be the Department of Environment, Great Lakes and Energy.


But here is some fun information. Again, check with your state for specifics.
*The rain garden location should be away from the house, sewer lines and underground utilities.  
*Keep away from drinking water wells and septic fields.
*The size depends on soil type as well as the size of the home, driveway, sidewalks and lawn.  Remember the garden probably won’t receive all the runoff.  It’s OK to design it to fit the amount received.
*A rain garden can handle runoff from an area 3 times its size.
* Soil test and drainage tests are important  These tests help determine the size of your garden and ensure it works.
*The garden must be located at a spot that drains well.  A functioning rain gardens absorbs water in 24 to 48 hours.


In addition to the benefits of rain gardens, now is the time to plan a new garden!  Late summer/early fall is a great time to plant.  Planting then allows plants to establish their roots before the winter season.  By next spring, it’s like an extra year has passed.  


What do I mean by “an extra year”?  There’s a saying about native plants, “They sleep, creep and then leap.”  The first year, the plant pretty much stays the same.  The second year, some slow growth happens.  The third year, the plant really takes off and grow by leaps and bounds.  When you plant in late summer/early fall, you get sleep and creep in 1 year.  The following spring should be time for the plant to put on a lot of growth (leap!).


What about choosing plants?  I like small plants—2” pots or plugs.  These tend to adapt well to a new site and, after 2 or 3 years, they look the same as quart-sized plants.  Look for shorter, compact plants.  More than one plant in a pot is fine if they all look healthy.  A few roots coming out the bottom shows good root development.  A tangle of roots means a pot-bound plant that may not grow well in its new home.


Which plants do well in a rain garden?  Surprisingly, all the plants need to tolerate dry periods.  That said, there are 3 zones in a raingarden.  Plants in the deepest zone tolerate recurring flooding or flow and dry spells.  These are usually tall to overcome the depth of the garden.

Intermediate zone plants thrive in average soil moisture but accept short periods of flooding or flow.  Finally, the plants on the edges grow well in dry conditions.  Edge plants are generally shorter.

As always, when planting a pollinator garden, choose a selection of plants that bloom from spring to fall.  In my rain gardens, I’ve used Golden Zizias (Zizia aurea), Black-Eyed Susans (Rudbeckia hirta), Rose Milkweed (Asclepias incarnata), Joe-Pye Weed (Eutrochium purpureum), and Smooth Aster (Symphyotrichum laeve).  I’ve discussed these plants before, but I thought I would discuss them as rain garden plants. 

Spring in the rain garden starts with Golden Zizias or Zizia aurea (https://wildthingsinthe.garden/2024/02/29/golden-lace-for-spring/).  In late spring to early summer, these lacey golden flowers welcome bees, wasps and beneficial insects.  These plants thrive in the intermediate areas and on the edges of the rain garden.  

As an early bloomer,  Zizia provides resources before many other plants and are always busy.  Some of its visitors include:  Hylaeus (Yellow-faced bees), Andrenid bees, Ceratina (small carpenter bees),  Osmia (Mason bees), Halictid bees including Lasioglossum, green metallic bees, wasps and its specialist bee Andrena ziziae.

Black-Eyed Susans or Rudbeckia hirta (https://wildthingsinthe.garden/2025/03/05/sunny-faces/) open next and continue into early fall.  Black-Eyed Susans, also, grow well on the edges and in the intermediate areas of the rain garden.

Numerous bees visit these cheerful flowers.  They include Honeybees (Apis spp.), Long-Horned Bees (Melissodes spp.), Leafcutter Bees (Megachile spp.), Cuckoo Bees (Coelioxys spp.), Sweat Bees (Halictus spp.), Green Sweat Bees (Agapostemon spp., Augochlorini Tribe), and Small Carpenter Bees (Ceratina spp.).  Rudbeckia hirta feeds several specialist bees, i.e.  including Andrena rudbeckiae, Pseudopanurgus albitarsis, P. rudbeckiae, Melissodes denticulatus, M. druriellus, M. illatus, Megachile pugnata, and M. xylocopoides.

Black-Eye Susan serves as a larval host for both moths and butterflies.  Wavy-Lined Emerald Moth ( Synchlora aerata), Southern Emerald Moth (Synchlora frondaria),  Common Eupithecia (Eupithecia miserulata), Gorgone Checkerspot Butterfly (Chlosyne gorgone), Bordered Patch Butterfly (Chlosyne lacinia) and Silvery Checkerspot Butterfly (Chlosyne nycteis) all lay eggs on R. hirta, 

Rose Milkweed or Asclepias incarnata (https://wildthingsinthe.garden/2025/04/01/a-delicate-pink-star/) begins flowering slightly later than Black-Eyed Susans and continues into the early fall.  Rose Milkweed serves well in the intermediate and deep portions of the  rain garden.  

As a Milkweed, it hosts the adult Monarch Butterflies at its blooms and is also a larval host.  In addition to supporting Monarch Butterflies, Rose Milkweed provides resources to native bees, Bumble Bees, Honeybees, beneficial insects and wasps.  Some specific examples are Sphecid wasps including the Great Black Wasp (Sphex pensylvanicus) and Great Golden Digger Wasps (Sphex ichneumoneus), Vespid wasps (Vespula spp.), Tiphiid wasps, Spider wasps, Paper Wasps (Polistes spp.), Square-Headed Wasps (Tachytesspp.), Bumblebees, honeybees, long-horned bees (Melissodes ssp, Svastra spp.), Yellow-Faced Bees (Hylaeus spp.), Sweat Bees (Lasioglossum spp.), Halictid Bees, Green Sweat Bees (Augochlorini Tribe), and Small Resin Bees (Heriades spp.).

Joe-Pye Weed or Eutrochium purpureum (https://wildthingsinthe.garden/2024/10/31/a-fabulous-fuzzy-flower/) blooms from mid-summer to early fall adding an additional source of pollen and nectar during the height of the season.  Plant Joe-Pye Weed in the intermediate and deep areas of the rain garden. 

It’s especially beloved by bees.  The bee visitors include Bombus spp. (bumblebees), Melissodes spp. (miner bees), Coelioxys (cuckoo bees), Agapostemon (metallic green sweat bees), Megachile spp. (leaf-cutting bees), Halictus spp., honeybees (Apis app.) and large and small carpenter bees, Xylocopa spp. and Ceratina spp.,

E. purpureum also invites a host of butterflies, moths, and skippers.  Celastrina (Azure Butterflies), Epargyreus clarus (Silver Spotted Skipper), Limenitis arthemis (White Admiral Butterflies), Nymphalis urticae (Milbert’s Tortoiseshell Butterflies), Papilio glaucus (Eastern Tiger Swallowtail Butterflies), and Danaus plexippus (Monarch Butterflies) sip the nectar from the fluffy, pink flowerheads

Smooth Blue Aster or Symphyotrichum laeve (https://wildthingsinthe.garden/2023/10/01/autumn-stars/) finish the growing season, blossoming from early to late fall.  Place this aster in the intermediate area or on the edge of a rain garden,

Enjoyed by native bees, this aster supplies nectar and pollen before the winter season.  Long- and short-tongued bees, honeybees, bumblebees, bee flies, wasps, butterflies, and beneficial insects all visit this plant.  Several specialist bees forage on Asteraceae plants including Andrena asteris, A. asteroides,  A. placata, A. simplex, Cnemidandrena hirtcincta, C. nubecula, and Colletes simulans.  

Soldier Beetles (Chauliognathus spp.), Insidious Flower Bug (Prius insidious), and chalcid wasps are beneficial insects that enjoy S. laeve.  Monarchs and other butterflies visit this aster for nectar during their fall migration.This aster also serves as a larval host for the Pearly Crescent Butterfly (Phyciodes thanos).

I hope you’ve enjoyed this application for your native plants.  It a wonderful time of year to begin a new garden area and rain gardens help your yard and the ecosystem!

Happy planting!

Mary

BIBIOGRAPHY:

  1. “Building a Rain Garden.” n.d. Accessed August 5, 2025. https://extension.umn.edu/landscape-design/rain-gardens.
  2. “Rain Gardens:  A Guide for Homeowners and Landscapers.” November 2018. Wisconsin Standards Oversight Council/Wisconsin Department of Natural Resources.
  3. Hinman, Curtis. June 2013. “Rain Garden Handbook for Western Washingtion:  A Guide for Design, Installation, and Maintenance.” Washington State Extension.
  4. Steiner, Lynn M. and Domm, Robert W. 2012. Rain Gardens:  Sustainable Landscaping for a Beautiful Yard and a Healthy World. Voyageur Press.
Categories
native plants Pollinator gardening

Moons in the Wetlands

The glowing spheres of Buttonbush blooms shine in its dark foliage.  The 2023 North Carolina Wildflower of the Year, Buttonbush (Cephalanthus occidentalis) thrives in difficult wet, low spots, even shallow standing water.  It supports pollinators, beneficial insects and is a larval host.   Cephalanthus occidentalis is also a rare mid-summer blooming shrub.

Buttonbush grows in zones 4-8.  It generally measures between 4 and 8 feet tall and spreads between 4 and 8 feet.  C. occidentalis enjoys full sun to part shade.  It flourishes in medium moisture to wet soils including shallow standing water and areas with occasional flooding.  Humusy soils, clay, loam, sand, shallow rocky soil, limestone soil, sandy loam, medium loam and clay loam all support Buttonbush.2, 3

Buttonbush grows in diverse wet habitats in nature.  These locations include wet open areas, low woods, floodplain forests, vernal pools in wooded areas, wet thickets, shrubby swamps, upland sinkholes, wet depressions in black soil prairies, marshes, bogs, seeps, seasonal wetlands, ponds, pond margins, lakes-often in water up to 3 inches, prairie swales, dry limestone bluffs, ditches, and borders of rivers, and streams.2,4

In addition to flourishing in wet conditions, Buttonbush tolerates various challenges.  It’s moderately deer resistant since its foliage contains a toxin.  This shrub works for erosion control.  Its swollen base stabilizes the plant.  It also survives competition, fire, and heat.4,12

If the species shrub becomes too big, rejuvenation pruning in early spring makes it more manageable.  Rejuvenation pruning is a technique used on multi-stemmed, twiggy shrubs.  The shrub is cut back to between 6 and 12 inches above the ground.  The individual stems are cut ¼ inch above a bud.  Cuts slope down and away from the bud at a 450 angle.   Remove dead wood as close to the ground as possible.  This method also works well Red-Twig Dogwood (Cornus sericea) and Pussy Willows (Salix discolor).7

If the species Cephalanthus occidentalis is still too large or unruly for your space, there is a smaller nativar. Buttonbush Sugar Shack grows to approximately 5 feet by 5 feet at maturity.  Sugar Shack is ball-shaped with compact growth.6

It enjoys the same conditions as the species-full to part sun and moist to wet soils.  The white flowers are similar in size and bloom from early to late summer (beginning to last blossom).  The seeds pods are red, becoming brown over the winter.  The foliage changes to burgundy in the fall.6

Foliage of Cephalanthus occidentalis is medium to dark green.  The leaves sit opposite each other in pairs or, occasionally, in whorls of 3.  They grow up to 6 inches long and 2.5 inches across.2

Each leaf has a smooth margin and an ovate or ovate-oblong shape.  Their upper surface is glossy, and the most common variety is hairless.  A pubescent (covered with soft, short hairs) variety also exists.  The foliage changes to yellow in the autumn.2

The spherical flowers start the show with Buttonbush.  They’re located at the top of branches or emerge from leaf axils.  These flowerheads grow from 1 to 2 inches across and are white or cream colored.2

Within the flowerhead, each floret consists of an approximately 1/3-inch-long corolla. It has 4 lobes at the opening.  There are 4 stamens and 1 undivided, white style.  The style extends beyond the floret opening.2

Buttonbush is self-incompatible and has an unusual way of releasing its pollen.  The stamens emerge first.  They shed pollen while the florets are still closed.  Then the florets open.  While the style elongates, it carries along the pollen and makes it accessible to bees and insects.

Cephalanthus occidentalis blooms for about 1 month.  The flowers are followed by red, round seedheads.  These remain throughout the winter turning brown and giving winter interest.2

Buttonbush feeds numerous creatures.  For the insects, C. occidentalis provides nectar and pollen and is of Special Value to Native Bees, of Special Value to Bumble Bees and Special Value to Honey Bees. XERCES Butterflies, moths and skippers, also, harvest resources from the flowers as well as wasps and flies. It’s also a larval host for many moths including the spectacular Titan Sphinx Moth (Aellops titan).2

Many different bees gather nectar from Cephalanthus occidentalis.  These include  Honeybees (Apis mellifera), bumblebees (Bombus), cuckoo bees (Triepeolus spp.), long-horned bees (Melissodes spp.), leaf-cutting bees (Megachile spp.), green metallic bees (Agapostemon spp.), small carpenter bees (Ceratina spp.), yellow-faced bees (Hylaeus spp.) and large carpenter bees (Xylocopa spp.).2

In the past,  Buttonbush support a large beekeeping industry along the lower Mississippi River floodplain where the shrub thrived.  It’s still known by the common names of Honeybush, Honeybells and Honeyballs.  Honeybees continue to seek out its nectar and pollen.13

Bumble bees frequently visit C. occidentalis when it’s flowering.

Small bees gather resources at Buttonbush, climbing in and out of the florets.  These pollinators include small carpenter bees (Ceratina spp.), green metallic bees (Agapostemon spp.), and yellow-faced bees (Hylaeus spp.).

There are 366 species of small carpenter bees (Ceratina spp.) throughout the world (except Oceania).  27 species live in the United States with 5 in the Eastern US and Canada.8,11  Despite their name, they’re not closely related to the carpenter bee, Xylocopa. 

 Ceratina are stem nesting bees that need pithy centers.  They nest in perennials and woody stems.  The female excavates a long nesting tunnel and uses the stem pith to create cell divisions.  Once the nest is full, the female guards the entrance.  She makes a yellow, strongly citral-scented secretion that is excreted from her mandibles (“jaws”).  The mother smears this on the nest entrance to repel predators.8,11

Ceratina show some unusual and fascinating social behaviors.  Unlike other bees, small carpenter bees live a long time, 12 to 16 months.  In temperate climates like the Northeast and Great Lake, this means through the winter.  

These bees care for their young throughout this time.  The mother removes the nest partitions each evening and grooms her young.  This behavior is believed to reduce parasites and remove any developing fungal infections from the nest.  These mother-offspring interactions separate Ceratina from other solitary bees and are considered subsocial.8,11

Various wasps drink nectar from Cephalanthus occidentalis.  Scoliid wasps (Dielis spp.), Carrot or Gasteruption wasps (Gasteruption spp.), and  Thynnid Flower wasps (Myzinum spp.) are solitary, parasitic or parasitoid wasps which visit Buttonbush.  In addition, the solitary wasps, Mason wasps (Monobia spp.), Cuckoo wasps (Parnopes spp.), (Pseudodynerus spp.), and Thread-Waisted wasp (Sphex spp). also use C. occidentalis.   Finally, the very social yellow jacket, (Vespula spp.) gathers nectar from this shrub.9

The Great Golden Sand Digger Wasp (Sphex ichneumoneus) is a beautiful, beneficial wasp.  This digger wasp hunts cicadas and true crickets to provision its nests.  The female constructs a vertical nest with 2 or 3 side cells for eggs. She lays her egg on the first prey and adds 1 to 5 more.  The number of nests per year vary depending on the length of growing season.  Like other solitary wasps, the Great Golden Sand Digger Wasp is not aggressive, and, in fact, the male doesn’t have a stinger.9,10

Thick-headed flies and Syrphid flies gather nectar from Buttonbush flowers.2

Buttonbush serves adult butterflies, moths and skippers.2,5,13  They visit its blooms for nectar.

Several moths use this shrub as a larval host including some spectacular ones.  The Titan Sphinx (Aellops titan), the Hydrangea Sphinx (Darapsa versicolor), and the  Royal Walnut Moth (Cithermia regalis) larvae all feed off the Cephalanthus occidentalis plant.2,5,13

Hope you’ve enjoyed this dive into Cephalanthus occidentalis!  Look for it blooming when you’re near water.  Check for it at the edges of wetlands by roadside ditches. 

Enjoy Summer and Happy Gardening,

Mary

BIBLIOGRAPHY:

  1. “Bird Table (Cephalanthus Occidentalis).” Accessed July 1, 2025. https://www.illinoiswildflowers.info/trees/tables/table283.html.
  2. “Buttonbush (Cephalanthus Occidentalis).” Accessed July 1, 2025. https://www.illinoiswildflowers.info/trees/plants/buttonbush.htm.
  3. “Cephalanthus Occidentalis – Plant Finder.” Accessed July 1, 2025. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=g830.
  4. “Cephalanthus Occidentalis (Buttonbush, Button Bush) | North Carolina Extension Gardener Plant Toolbox.” Accessed July 1, 2025. https://plants.ces.ncsu.edu/plants/cephalanthus-occidentalis/.
  5. “Cephalanthus Occidentalis (Common Buttonbush) | Native Plants of North America.” Accessed July 1, 2025. https://www.wildflower.org/plants/result.php?id_plant=ceoc2.
  6. “Cephalanthus Occidentalis ‘SMCOSS’ SUGAR SHACK – Plant Finder.” Accessed July 1, 2025. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=443503&isprofile=0&.
  7. Fogerty, Elane, New Jersey Agricultural Experiment Station.  Pruning Flowering Shrubs.  Cooperative Extension Fact Sheet FS1221.  December 2013.
  8. Holm, Heather. Bees:  An Identification and Native Plant Forage Guide. Minnetonka, MN: Pollination Press LLC, 2017.
  9. Holm, Heather. Wasps:  Their Biology, Diversity, and Role as Beneficial Insects and Pollinators of Native Plants. Minnesota: Pollination Press LLC, 2021.
  10. Missouri Department of Conservation. “Great Golden Digger Wasp.” Accessed July 1, 2025. https://mdc.mo.gov/discover-nature/field-guide/great-golden-digger-wasp.
  11. Rehan, Sandra M. “Small Carpenter Bees (Ceratina).” In Encyclopedia of Social Insects, edited by Christopher K. Starr, 1–4. Cham: Springer International Publishing, 2020. https://doi.org/10.1007/978-3-319-90306-4_106-1.
  12. Wennerberg, Sarah. USDA NRCS. Plant Guide:  Common Buttonbush, Cephalanthus occidentalis L. Plant Symbol=CEOC2, Last edit:  05 June 2006, https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_ceoc2.pdf
  13. Xerces Society. “Planting for Pollinators: Button Bush.” Accessed July 1, 2025. https://www.xerces.org/blog/planting-for-pollinators-button-bush.
Categories
native plants Pollinator gardening

A White, Frilly Flower

Fluffy and flexible, Eupatorium perfoliatum (Boneset or Thoroughwort) thrives in the garden.  It adapts to a multitude of growing conditions so it’s able to fill tough spots.  Best of all, pollinators and beneficial insects flock to the frothy, white blooms.

Chosen 2003 North Carolina Wildflower of the Year, E. perfoliatum grows in zones 3 through 8.  The plants range in height from 2 feet to 6 feet.  They spread from 2 feet to 4 feet across.2,9,10

Boneset prefers sun to part sun, moist to wet soils with organic matter and continuous moisture.  But it tolerates shade, periodic flooding, sand and clay soils.  I have a beautiful plant growing in the backfill sand next to my house–in complete shade!2

In natural settings, Eupatorium perfoliatum grows from the East Coast almost all the way west to the Rocky Mountains. Its natural habitats include openings in floodplain forests, poorly drained areas of black soil prairies, various wetlands—marshes, bogs, fens, seeps, edges of rivers, edges of ponds, sand flats, thickets, stream banks, wet meadows, wet prairies and ditches.  Boneset enjoys disturbed areas.  It flourishes on the edges of rain and water gardens.1,2

E. perfoliatum’s leaves are light green in color and have a rough, wrinkled texture.  They’re smooth on top and hairy on the bottom.  The foliage grows opposite on the stem.1   

The leaf bases wrap around the stem so it looks like the stem pierces them.  They are lance-shaped with toothed edges.  They can grow up to 8 inches long and 2 inches across.1,9

Boneset’s flowerhead crown the plant.  Groups of florets combine to form a 2- inch to 8-inch flower.  The individual florets are 1/6 inch or 4 mm across.  They have about 15-disc floret but no ray florets (or petals).1

Each disc floret has 5 spreading lobes, a brown column of stamens and a divided style.  Other Eupatorium spp. have the same flower structure including Joe-Pye Weed (Eupatorium maculatum,https://wildthingsinthe.garden/2024/10/31/a-fabulous-fuzzy-flower/).  Eupatorium perfoliatum blooms from late summer to early fall.  The overall bloom time for a clump is 1 to 2 months.  The flowers have a pleasant scent.1,9

Boneset has fibrous roots.  Plants usually spread by rhizomes.   If happy, they form large colonies.  In good conditions, E. perfoliatum self-seeds.  My garden has areas that flood regularly when it rains especially in the spring.  I’ve had Boneset appear in these areas and in pots.

Eupatorium perfoliatum draws masses of pollinators and beneficial insects.  The Xerces Society for Invertebrate Conservation designates it of ‘Special Value to Native Bees’ and states it ‘Supports Conservation Biological Control’.  Boneset also serves as a larval host for numerous moths.

Multitudes of bees, big and small, visit Boneset.  The little bees include Yellow-Faced Bees (Hylaeus spp.),  Sweat bees (Lasioglossum spp.  and Halictus spp.), Augochlora pura, Green Sweat Bees (Agapostemon spp.), Mining Bees (Andrena spp.),  and Bumble Bees ( Bombus spp.).

Eupatorium perfoliatum strongly supports wasps of all kinds.  At least 102 different species gather nectar from it.  Many of these wasps contribute to the garden as beneficial insects.  Some examples are Sand Wasps (Bicyrtes spp.), Paper wasps (Polistes spp.), Bald-Faced Hornets (Dolichovespula spp.), Bee Wolves (Philanthus spp.), Beetle Wasps (Cerceris spp), Potter Wasps (Eumenes spp.), Grass-Carrying Wasps (Isodontia spp.), Thynnid Wasp (Myzinum spp.), Cuckoo Wasp (Hedychrum spp.), and Thread-Waisted Wasps (Eremnophila aureonotata). 

While supporting biological controls, Boneset plays host to some unusual flies, beetles and other insects.  Flies include Tachinid flies (Gymnoclytia spp., Archytas spp., Trichopoda spp.,  Juriniopsis adusta), Syrphid Flies (Eristalis spp. and Helophilus spp.), Thick-Headed Flies (Physocephala spp.) and Bee Flies (Villa spp.).

Tachinid flies are beneficial insects in their role as parasitoids.  As parasitoids, their larvae feed on, and eventually kill, other insects.  These flies lay eggs on leaves or on the insect itself.  If an egg hatches outside the host, the maggot eats its way inside.  An insect may also eat the egg.  Then the larvae hatches inside the prey’s body.5

While many tachinid flies look like plump, spiny houseflies, there are some wonderfully strange and fantastic species.  Two examples are Juriniopsis adusta and Trichopoda spp.5

 Juriniopsis adusta (no common name) is a ghostly-looking fly with a red abdomen covered in black bristles.  It’s a quick fly that rarely lights for a long time.  The larvae eat caterpillars.  I chased this one for 2 years before I got the photos I wanted.5

Trichopoda spp.  or Feather-Legged Flies are bee mimics.  They’re a stunning fly with feathery bristles on the hind legs to mimic a pollen basket and jet-black wings with clear edges.  The males have bright orange abdomens.  The young of Feather-Legged Flies are parasitoids of true bugs including squash bugs, plant bugs, stink bugs, leaf-footed bugs and shield-backed bugs.3,5

Entomologists at Michigan State University studied insects attracted to Eupatorium perfoliatum.  They found that it was 20 times more attractive to beneficial insects than the grass control.  Boneset was Highly Attractive for Insidious Flower Bug (Orius insidiousus), Plagiognathus politus- a flower bug, (Chalcidoidea), and soldier beetles (Cantharidae).  At the Moderately Attractive level, it drew crab spiders (Thomisidae) and Cynipoidea-a family of parasitoid and gall-forming wasps. Finally, E. perfoliatum was Mildly Attractive for Sphecid wasps, lady beetles (Coccinellidae), Jumping Spiders (Salticidae), Braconidae-a parasitic wasp family and damsel bugs (Nabidae).4  

Not mentioned in the MSU study, the jagged ambush bug (Phymata spp.) happily lives and breeds on my blooming Boneset.  This fierce bug has huge raptor-like front legs.  Like its name, the jagged ambush bug hides in flowers and ambushes its prey.6,7 

Using speed and the raptor-like legs, it captures insects up to 10 times its size.  Once caught, the ambush bug uses venom to paralyze the prey and liquify the internal organs.  Then, it drinks the bodily fluids with a straw-like mouth part.6.7

The adult ambush bugs hunt from the flowers while the immature bugs (called nymphs) use other parts of the plant.  The adults and nymphs eat mites, aphids, leafhoppers, thrips, caterpillars, mealybugs, beetles, scale insects, insect eggs.  Adults also eat flies, bees and wasps.6,7

Eupatorium perfoliatum acts as a larval host for several moth species.  Their larvae use different parts of the plant.  They include Geometrid Moths (Semiothisa continuata), Clymene Moth (Haploa clymene ), Three-Lined Flower Moth (Schinia trifascia), Blackberry Looper Moth (Chlorochlamys chloroleucaria), Burdock Borer Moth (Papaipema cataphracta ), and Lined Ruby Tiger Moth (Phragmatobia lineata).1,10

Eupatorium perfoliatum is the plant for many places.  An adaptable garden plant, it’s happy living in a variety of growing conditions.  It adds blooms to the late season garden with its white, fluffy flower heads.  Boneset serves as a pollen and nectar source and as a larval host, drawing pollinators and beneficial insects alike!

I hope you’ve enjoyed this latest blog.  I’d love to hear from you with a question or a comment.  Hope everyone is enjoying the new garden season!

Happy Gardening,

Mary 

Bibliography:

  1. “Common Boneset (Eupatorium Perfoliatum).” Accessed May 30, 2025. https://www.illinoiswildflowers.info/prairie/plantx/cm_boneset.htm.
  2. “Eupatorium Perfoliatum – Plant Finder.” Accessed May 30, 2025. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=277187.
  3. Missouri Department of Conservation. “Feather-Legged Flies.” Accessed May 30, 2025. https://mdc.mo.gov/discover-nature/field-guide/feather-legged-flies.
  4. Native Plants and Ecosystem Services. “Common Boneset.” Accessed May 30, 2025. https://www.canr.msu.edu/nativeplants/common_boneset.
  5. Missouri Department of Conservation. “Parasitic Flies (Tachinids).” Accessed May 30, 2025. https://mdc.mo.gov/discover-nature/field-guide/parasitic-flies-tachinids.
  6. “Predatory Bugs : Ambush Bugs | Hortsense | Washington State University.” Accessed May 30, 2025. https://hortsense.cahnrs.wsu.edu/fact-sheet/predatory-bugs-ambush-bugs/.
  7. Galveston County Master Gardeners. “Jagged Ambush Bug,” May 31, 2025. https://txmg.org/galveston/beneficials-in-the-garden-and-landscape/jagged-ambush-bug/.
  8. Lady Bird Johnson Wildflower Center. “Lady Bird Johnson Wildflower Center – The Botanic Garden of Texas,” June 1, 2025. https://www.wildflower.org/.
  9. “Eupatorium Perfoliatum (American Boneset, Boneset, Bonset, Feverwort, Thoroughwort) | North Carolina Extension Gardener Plant Toolbox.” Accessed May 30, 2025. https://plants.ces.ncsu.edu/plants/eupatorium-perfoliatum/.
  10. United States Department of Agriculture-Natural Resources Conservation Service, Plant Fact Sheet, Common Boneset, Eupatorium perfoliatum L., USDA-NRCS.
Categories
native plants Pollinator gardening

A Delicate Pink Star

The elaborate blooms of Asclepias incarnata (a.k.a. Swamp Milkweed or Rose Milkweed) draws crowds of pollinators and beneficial insects.   Like other milkweeds, Rose Milkweed feeds Monarch butterfly caterpillars.  This milkweed received the 2005 North Carolina Wildflower of the Year award.  The North Carolina Botanical Garden and the North Carolina Garden Club co-sponsor this award.3

 Asclepias incarnata varies in height from 2 to 5 feet but is typically 3 to 4 feet.  It spreads from 2 to 3 feet.  Rose milkweed grows in zones 3 through 9.3

Although it thrives in medium to wet, neutral to slightly acidic soils with full sun, it adapts to a variety of conditions.  Rose milkweed is one of the few ornamentals that grows in mucky clay.  It tolerates average to occasionally wet soils. high organic matter soils and loam (silt) soils.3,4,5,6,7

In nature, Rose milkweed is found in sunny openings and edges of swamps, river bottomlands, wet meadows, marshes, bogs, fens, open areas along stream banks and ditches, open to partly shaded areas in floodplain forests, thickets, moist black soil prairies, low areas around rivers and ponds, seeps, fens and marshes.  It grows in both natural and disturbed areas.3,7

I’ve grown Rose Milkweed for several years.  Moisture varies across my garden from with average to wet.  In the average soils, Asclepias incarnata plants grow to gorgeous specimens 4 feet high and across.  Unfortunately, then it dies back to one or two shoots.  I never lose it completely though since it reseeds several new plants every year.

I’ve created a rain garden including Rose Milkweed.  The rabbits ate it the first year so I’m waiting to see how this milkweed recovers.  It’s unusual for herbivores to bother Asclepias incarnata.  This plant has the same milky latex sap as other milkweeds.  This sap has bitter tasting cardiac glycosides which taste bad and can make animals ill.3,7

The foliage of Rose Milkweed is medium to dark green on light green, smooth stems.  Its leaves are opposite and touching or clasping the stem.  They are usually 3 inches long and 0.5 inch wide but can grow up to 6 inches long and 1.5 inches wide.3

The leaves are narrowly lanceolate or oblong-lanceolate in shape.  Their edges are smooth (entire).  When the plants are stressed, in sunny, dry conditions, the leaves may turn yellowish-green or pale green.3,7

The wonderfully intricate flowers of Asclepias incarnate resemble those of other milkweeds.  They can be pink, purple or, rarely, white and bloom from early Summer to early Fall.  The umbels of florets form at the top of stems.  Each floret is 0.25 inch across with 5 upright lighter colored hood petals and 5 surrounding darker petals shape, fused stigmas (the female parts) form the column.2,3,7

Like other milkweeds, Rose milkweed carry their pollen in waxy sacs called pollinia.  Pollinarium (Pollinaria plural) is the structure that holds the pollinia.  Each pollinia has 2 pollinia attached to translator arms.2  

In the center is a blackish-brown gland (corpusculum) with a slit.  At the end of the translator arm, just before each sac, is a 900 bend.  This bend lets the sacs rotate during pollination.  Pollinaria sit in a slit in stigmatic column. The corpusculum rests on the outside.2

Insects land on  Asclepias incarnata looking for nectar.  The five intricate upright petals have cup-like nectar reserves and downward-curved horns.  Insects sometimes slip on the horns and a leg slides between two petals into the stigmatic slit.2  

Large Carpenter Bee with pollinaria on front legs.

As it tries to get free, bristles in the chamber keep it from going back down.  Not all insects escape.  Small insects can be trapped and die.  Others lose legs.  But medium to large size bees, wasps and butterflies do remove pollinarium and go on to pollinate other milkweed plants.2

How does pollination actually occur?  I’m glad you ask because it’s amazing!  After it’s removed, the pollinarium starts drying out.  The sacs rotate 900 as it dries.  The rotation moves them into the correct position for pollination.2

Once the sacs are in position, the knee bend (not the center oval) slides into the space between the petals.  The arm follows the pollinial sac into the space in the stigmatic column. Then the arm breaks off releasing the insect and pollination is complete.2

An intricate and delicate process where timing (for drying) and the mechanics of the insect’s motion and the pollinaria all play a crucial role!

Like other milkweeds, Asclepias incarnata  supports numerous insects including pollinators and beneficial insects.  The Xerces Society for Invertebrate Conservation classifies Rose Milkweed as of Special Value to Native Bees, Special Value to Bumble Bees, and Special Value to Honey Bees.  In addition, they declare it Supports Conservation Biological Control (beneficial insects).  Milkweeds are also the only larval host for the Monarch butterfly (Danaus plexippus).3,5

Bee visitors include bumblebees (Bombus spp.),

honeybees (Apis),

long-horned bee (Melissodes ssp, Svastra spp.), Yellow-Faced Bees (Hylaeus spp.), Sweat Bees (Lasioglossum spp.), Halictid Bees, Green Sweat Bees (Augochlorini Tribe), Small Resin Bees (Heriades spp.)

and Leafcutter Bees (Megachilespp).5,7,8,9

Wasps also harvest nectar from Rose Milkweed.  They include Sphecid wasps, Vespid wasps (Vespulaspp.), Tiphiid wasps, Spider wasps, Paper Wasps (Polistes spp.) and Square-Headed Wasps (Tachytesspp.).  The Great Black Wasp (Sphex pensylvanicus) and Great Golden Digger Wasps (Sphex ichneumoneus) are two Sphecid wasps that use the nectar.5,7,9

Flies gather nectar from Asclepias incarnata.  Mydas flies, thick-headed flies, Tachinid flies (Archytas spp.), Bee flies (Bombylius spp. and Villa spp.), Green Bottle flies (Lucilia spp.) and Syrphid flies (Tropidiaspp.).5,7,9

Butterflies, moths and skippers seek out Rose Milkweed for nectar and as a larval host.  Swallowtail butterflies, Greater Fritillaries, Great Spangled Fritillaries (Speyeria cybele), Red Admiral (Vanessa atalanta), Hummingbird Clearwing Moth (Hemaris spp.), Monarch butterflies, and skippers including the Family Hesperiidae.3,4,5,7

Monarch Butterfly on Common Milkweed
Fritillary butterfly on Common Milkweed
Eastern Tiger Swallowtail on Common Milkweed.

Another occasional visitor of the flowers is the Ruby-Throated Hummingbird.4,5,7

Various insect feed on parts of Asclepias incarnata including leaves, flowers and seeds.  These insect feeders include Labidomera clavicollis (Swamp Milkweed Leaf Beetle), Tetraopes spp. (Red Milkweed Beetles), Oncolites fasciatus (Large Milkweed Bug), and Aphis nerii (Yellow Milkweed Aphid).5,7,9 

Milkweed Bug on Common Milkweed

I hope you’ve enjoyed this adventure with Rose Milkweed.  All the insects love a milkweed and it’s always worth stopping by the milkweed patch to see whose around!

Hope you’re enjoying Spring!

Happy Gardening,

Mary

BIBLIOGRAPHY

  1. Borders, B., Casey, A., Row, J., Wynia, R., King, R., Jacobs, A., Taylor, C., & Mader, E., Pollinator Plants of the Central United States:  Native Milkweeds (Asclepias spp.), 2013.
  2. Eldredge, Eric. “Milkweed Pollination Biology,” n.d.
  3. Asclepias Incarnata (Marsh Milkweed, Swamp Butterfly Weed, Swamp Milkweed) | North Carolina Extension Gardener Plant Toolbox.” Accessed April 1, 2025.  https://plants.ces.ncsu.edu/plants/asclepias-incarnata/.
  4. “Asclepias Incarnata – Plant Finder.” Accessed April 1, 2025. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=g410
  5. “Asclepias Incarnata (Swamp Milkweed) | Native Plants of North America.” Accessed April 1, 2025. https://www.wildflower.org/plants/result.php?id_plant=asin.
  6. “Plant of the Week:  Swamp Milkweed (Asclepias incarnata L.).” Accessed April 1, 2025. https://www.fs.usda.gov/wildflowers/plant-of-the-week/asclepias_incarnata.shtml.
  7. “Swamp Milkweed (Asclepias Incarnata).” Accessed April 1, 2025. https://www.illinoiswildflowers.info/wetland/plants/sw_milkweed.htm.
  8. Holm, Heather. Bees:  An Identification and Native Plant Forage Guide. Minnetonka, MN: Pollination Press LLC, 2017.
  9. Holm, Heather. Pollinators of Native Plants:  Attract, Observe and Identify Pollinators and Beneficial Insects with Native Plants. Minnesota: Pollination Press LLC, 2014.
Categories
native plants Pollinator gardening

A Wild and Wacky Plant

Clouds of beneficial wasps and small bees swarm the crown of tiny, white flowers.  Flowerheads rise on stalks up to nine feet tall offering stunning vertical accents in the garden.  This is Arnoglossum atriplicifolium one of several Arnoglossums native to Eastern North America.  

Why is this plant so different? The flowers don’t have any petals, only disk florets.  Disk florets usually make up the center of a bloom and are surrounded by ray florets or petals.

The leaves seem to defy description.  They’ve been called triangular or oval-cordate or oval but none of these is right.  The closest I’ve heard is Sycamore-like, with undulate edges (rippled edges).

The leaf texture is also unique.  Thick and shiny, it’s been compared to leather or plastic.  All these characteristics come together in a striking plant.2,6

Arnoglossum atriplicifolium grows in full sun to light shade.  Loamy, rocky or sandy soil are all acceptable.  But this plant loves evenly moist soil that stays constantly wet.  When Arnoglossum is happy, it reseeds freely.  Cut back the flower stalks to avoid this issue.1,6,9

In nature, Arnoglossum appears in open and rocky woodlands, thickets, wet meadows, along streams, in mesic forests, savannahs, woodland edges, sand dunes, rocky clearings in woodlands, prairies, meadows, upland woodlands, wooded slopes, slopes of ravines, sandy savannahs, sandy thickets, partly shaded thickets, and partly shaded banks near Lake Michigan.2,6

The first year, Arnoglossum atriplicifolium forms as a basal rosette of medium to dark green leaves.  These leaves grow up to eight inches long and six inches across.  While the top sides are green, the lower leaf surfaces are pale greenish white to bright white.  

In the second or third year, a stalk appears in Spring and grows to between three and nine feet tall with alternate leaves.  The unbranched stalk provides an erect accent in the garden.  These leaves become smaller as they go up the stalk.  Cavity nesting bees and wasps use the hollow stems for nesting.1,2,6,9

Flat-topped flowerheads (technically called a compound corymb) develop at the top of the plant stalk.  Without petals, the flowerhead make up their size by grouping four to fifteen florets together into corymbs.  These corymbs grow together to form the whole flowerhead.9  

The individual florets are about an eighth inch across and a third inch long with five disk florets.  Each one has a style that extends beyond its end.  The styles are bipartite which means two styles joined together.  As they mature, the tips curl away from each other forming circles.  Anthers also reach past the end of the floret.6

Arnoglossum atriplicifolium is self-incompatible.  Each floret must be fertilized with pollen from a different plant. Wasps, small bees and flies provide pollination.3

Blooms appear in mid-Summer and continue into early Fall.   Total flowering time is about one month.  Cut it back for a smaller second bloom.6

Adding to the overall wackiness of Arnoglossum, the most common visitors are predatory or parasitoid wasps.  Some of which look very scary indeed!  These wasps are also beneficial insects helping to control many garden pests.  In fact, the Xerces Society for Invertebrate Conservation labeled Arnoglossum as Supports Conservation Biological Control.

Wasps prefer dilute nectar on hot summer days and Arnoglossum is an excellent source of late season nectar.  The nectar secretes at the base of the style.  It’s drawn up the corolla so even short-tongued wasps.  White flowers keep the nectar cool and dilute.3

Thirty-four different species of wasps visit Arnoglossum atriplicifolium.4  These include, Sand Wasps (Bicyrtes spp.), Great Black Wasps (Sphex pensylvanicus), Great Golden Digger Wasps (Sphex ichneumoneus), Thread-Waisted Wasps (Ammophila spp.), Potter Wasps (Eumenes spp.), the Common Yellowjacket Wasp (Vespula spp.), and Grass-Carrying Wasps (Isodontia spp.).3

Are Yellowjackets beneficial?  It’s hard to feel that way.  They’re scary, the stings are painful, and they can ruin your picnic.  Vespids or Yellowjacket wasps can send you to the ER too, if you’re allergic to their sting.  So, is there an upside?

WARNING:  Yellowjacket or Vespid wasps form large colonies.  When disturbed, they’ll attack as a group.  Multiple stings are dangerous even to non-allergic individuals.

Do not allow nests around people, especially children, animals and especially those with allergies. Also, do not attempt nest removal yourself! Use a professional exterminator!

OK back to beneficial insects—Yellowjacket wasps build yearly nests.  Their mated queens overwinter in cozy spots like bumblebees.  In the Spring, the queens establish a nest and lay eggs to become workers.  The workers will continue building the nest and gathering prey.

Almost all Vespid wasps (Yellowjackets), use chewed wood pulp and saliva to create paper nests.  Different types of Vespids choose different locations for homes.  Options include holes like openings in trees, structural walls, abandoned animal burrows or rotting tree stumps or aerial places in trees or under building eaves.  Often nests aren’t noticed until they’re large or disturbed.11

But what good are they?  Colony size ranges from a few hundred to over 5,000.  Almost all these wasps hunt for insect prey and many prey on pests.  Depending on the species, Vespids target crickets, grasshoppers, spiders, flies, and fall webworms.  Those that live in trees and high places frequently gather food there.11

I wouldn’t let Yellowjacket set up housekeeping in my yard especially near children, animals, individuals allergic to bee stings or other human activity.  But you have a place on your property, where they won’t be disturbed, a Vespid nest is like a small army of pest control.

Many small bees gather nectar and pollen from Arnoglossum atriplicifolium.  Sweat Bees (Halictus sp. and Lasioglossum sp.) and small Carpenter Bees (Ceratina sp.) are some of the short-tongued bees seen.

Halictid or Sweat Bees fall in the small and mighty category of pollinators.  There are more than 500 species in North America.  In the garden and in natural area, they are more plentiful than most other native bees.7,8

Almost all are ground nesting but the colony structure can be solitary, communal, semi-social or eusocial.  Sometimes these nesting behaviors vary with time of year, location-geographic and altitude, and for reasons we don’t understand.5,7,8

Two fun facts about the Halictid bees are:  they drink human sweat and they can buzz pollinate.  Why do they lap up sweat?  It’s like an electrolyte drink for them.  On hot summer day, Halictid bees need some salt and other minerals.  Human perspiration is one easy source!5,7,8

What about buzz pollination?  Buzz pollination is sometimes called sonication.  A sweat bee holds onto a flower’s anther with its mandibles and curls its abdomen around the anther.  It vibrates its wing muscles to release pollen.5  

Many flowers need buzz pollination to effectively free their pollen.  These plants include the heath family (blueberry, cranberry) and nightshade (tomato, groundcherry, pepper, eggplant, potato),  A number of native bees can buzz pollinate, most famously, the Bumblebee.  Honeybees cannot.5,10

Lastly, flies gather nectar and pollen at Arnoglossum atriplicifolium.  Syrphid flies frequently stop to sip the accessible nectar.3

Bonus Bug: Both male and female mosquitos visit flowers for nectar. Females need blood for the protein and most use a sugar source. Males need a sugar source, like nectar, to survive. We don’t know how they choose particular flowers but they are attracted to some chemical compounds.12

Hope you enjoyed this look into a Wild and Wacky plant!  Arnoglossum atriplicifolium benefits some bizarre and wonderful insects as well as some more familiar ones.  It delivers a wonder accent in the garden and is an excellent source of late summer nectar!

Warm Regards,

Mary                            

References:

  1. “Arnoglossum Atriplicifolium – Plant Finder.” Accessed September 2, 2024 https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=293225.
  2. “Arnoglossum Atriplicifolium (Pale Indian Plantain) | North Carolina Extension Gardener Plant Toolbox.” Accessed September 2, 2024. https://plants.ces.ncsu.edu/plants/arnoglossum-atriplicifolium/.
  3. Holm, Heather. Pollinators of Native Plants:  Attract, Observe and Identify Pollinators and Beneficial Insects with Native Plants. Minnesota: Pollination Press LLC, 2014.
  4. Holm, Heather. Wasps:  Their Biology, Diversity, and Role as Beneficial Insects and Pollinators of Native Plants. Minnesota: Pollination Press LLC, 2021.
  5. Missouri Department of Conservation. “Halictid Bees (Sweat Bees).” Accessed September 2, 2024. https://mdc.mo.gov/discover-nature/field-guide/halictid-bees-sweat-bees.
  6. “Pale Indian Plantain (Arnoglossum Atriplicifolium).” Accessed September 2, 2024. https://www.illinoiswildflowers.info/savanna/plants/pale_indplant.htm.
  7. “SWEAT BEES: GENUS LASIOGLOSSUM | The Great Sunflower Project.” Accessed September 2, 2024. https://www.greatsunflower.org/Lasioglossum#.
  8. “Sweat or Halictid Bees.” Accessed September 2, 2024. https://entnemdept.ufl.edu/creatures/misc/bees/halictid_bees.htm#
  9. “Weird and Wonderful Plants for Pollinators: Pale Indian Plantain | Xerces Society.” Accessed September 1, 2024. https://xerces.org/blog/pale-indian-plantain.
  10. Xerces Society. “Delectable Native Plants Attract a Very Special Crowd.” Accessed September 2, 2024. https://xerces.org/blog/delectable-native-plants-attract-very-special-crowd.
  11. “Yellowjackets and Baldfaced Hornets | CALS.” Accessed September 2, 2024. https://cals.cornell.edu/new-york-state-integrated-pest-management/outreach-education/whats-bugging-you/bees-and-wasps/identifying-bees-and-wasps/yellowjackets-and-baldfaced-hornets
  12. “Not Just from Blood: Mosquito Nutrient Acquisition from Nectar Sources – ScienceDirect.” Accessed September 2, 2024. https://www.sciencedirect.com/science/article/pii/S1471492220300404#.
Categories
native plants Pollinator gardening

A Summer Cornucopia

Part 2

And we’re back for Part II of The Summer Cornucopia!  Today the focus is on insects and how they use Common Milkweed.  If you missed Part I and are interested in the plant and pollination, here’s a link: https://wordpress.com/post/wildthingsinthe.garden/1831.

Asclepias syriaca draws an abundance of insects.  The sap, leaves and flowers are all used for food while blooms provide nectar to many insects.  Common Milkweed supports different life stages of flies, wasps, bees, butterflies, moths, skippers, plant bugs and beneficial insects.  Even hummingbirds try to sip nectar although they can’t reach it.1,7  

The most famous visitor to Common Milkweed is the Monarch butterfly (Danaus plexippus).  Monarchs can only use milkweeds (Asclepias) to feed their caterpillars. Growing milkweed supports the generations of Monarchs that hatch over the summer months.  When the last summer generation is born and transforms into an adult, they’ll drink nectar from milkweed and other flowers for food and fuel for their migration.8  

Growing native milkweeds helps preserve the existing Monarch population.  If you’re interested in helping Monarchs, Monarch Watch has excellent information on creating Monarch Waystations at https://www.monarchwatch.org/waystations/ .  Here are the highlights of the plan!8

How big does a waystation have to be?  Any size will help the Monarchs (and other pollinators!).  If possible, a 100 square foot waystation is highly effective.  The area doesn’t have to be all in one spot.  There can be several plantings throughout a property.

Sun is important for Monarchs.  Like other insects, they need heat and sunlight to warm themselves for flying and daily activities.  An area with six or more hours of sunlight is required.  Coincidentally, most milkweeds thrive under those conditions.

Milkweed also grow well in well-drained soil.  Place Monarch Waystations in low clay areas with fast draining soils.

Place plants close together (although not closer than recommended).  Monarchs and their caterpillars need shelter and protection from predators and the weather.

What about milkweed?  At least ten plants are recommended preferably with two or more types of milkweeds.  This planting scheme gives an extended season of bloom and allows the Monarchs longer access to the milkweed plants and nectar.  One type of milkweed is okay if more than ten plants are included.

Establish continuous supply of nectar plants.  Use annual, biennial and perennial plants.  Native plants are a great choice.  These plants also benefit the other pollinators.

Finally, create a management plan.  How will the waystation be maintained?  The plan contains basic garden maintenance:  mulching, fertilizing, removing invasive plants.  Additionally, it includes Monarch specific items:  eliminate insecticides, add more features like a water source or puddling spot.

Again, for more information on Monarch Waystations and other resources, including free milkweed programs, go to https://www.monarchwatch.org/waystations/

In addition to Monarchs, swallowtails (Papilio), fritillaries (Speyeria), viceroy butterflies (Limenitis), sulfurs (Pieris), and other butterflies also visit Asclepias syriaca.  Skippers use Asclepias syriaca for nectar including Ancyloxipha.1,7  

Common Milkweed is a larval host for the striking Milkweed Tussock Moth (Euchaetes egle) caterpillar, the Unexpected Cycnla (Cycnia inopinates) and the Delicate Cycnia (Cycnia tenera).  All are part of the group Artiinae or Tiger Moths.1  

The Delicate Cycnia (Cycnia tenera) lacks the usual aposematic coloration  It has a soft tan larva and a charming white adult with just a touch of orange on the head and wing edges.  Instead, it emits aposematic ultrasound calls when caught!  Bats release their prey when they hear the calls.  During the day, their color variation seems to keep birds away.1,9

Both long-tongued and short-tongued bees visit Common Milkweed for nectar.  These include honeybees (Apis),

Bumble Bees (Bombus),

leaf-cutter bees (Megachile),

cuckoo bees (Coelioxys), small carpenter bees (Ceratina)

and sweat bees (Halictus and Lasioglossum).1,7,10

Many wasps enjoy nectaring at Milkweed flowers especially Sphex, Tachytes, Polistes,  Myzinum, and ichneumon wasps.  Sphex ichneumoneus is a known pollinator of Common Milkweed.1,7

Numerous beneficial insects visit Asclepias syriaca including the delicate and diverse ichneumon wasps.  The adult wasps use milkweeds’ nectar for fuel while searching for insect prey.  They’re considered parasitoids and the females lay eggs inside grubs and caterpillars.  

Young of boll weevils, tomato hornworms and wood borers are all food for ichneumon wasps.  In addition to garden pests, adults hunt large insects such as spiders and butterflies.  

In general, ichneumon wasps help reduce the number of insects that reach reproductive age.  Many of these prey insects damage trees.  In this way, the wasps help keep trees healthy.11

Bembix americana, a predatory sand wasp, also gathers nectar from Common Milkweed.  B. americanafeeds their young true flies (Diptera).  Diptera include house flies, gnats and mosquitos.  

As populations of flies increase, B. americanas numbers rise.  A single larvae can eat two dozen flies.  B. americana uses a different strategy for provisioning its young.  Other wasps paralyze their prey and stock each cell with the required (living but paralyzed) insects.  This sand wasp kills the flies and adds more food as needed.12

Asclepias syriaca hosts predatory stink bug larvae.  Stink bugs have a terrible reputation especially since the arrival of  the invasive Brown Marmorated Stink Bug.  But predatory stink bugs are a whole different category.  These are beneficial insects that hunt insect prey.  

Above, is a photo of a Spined Soldier Bug larvae on milkweed.  There are five larval stages (instars) and all eat insects.  Their preferred foods include Mexican bean beetle, Colorado potato beetle, and imported cabbageworm.  

Look for the adult Spined Soldier Bug on plants where prey may be located.  These plants include the melons/squash/cucumber (cucurbit), broccoli, cauliflower, kale, etc. (cruciferous) and tomatoes, peppers, eggplant (solanaceous) crops.  

If you’re looking for eggs, they’re an incredible metallic bronze color with a row of spines like a crown.  Just hatched larvae, cluster around the eggs eating necessary bacteria.  Spined Soldier Bug can be purchased commercially.13

In addition to all these, Asclepius syriaca hosts many beetles and bugs,

grasshoppers,

and leafhoppers

Finally, flies, including beneficial ones, nectar on Asclepius syriaca.

I hope you’ve enjoyed this exploration of the insects found on Common Milkweed.  Pollinators and beneficials all enjoy Asclepias.  It’s always worth stopping to see who’s home in the milkweed patch with or without flowers!

Happy Gardening, Mary

References

  1. Hilty, J., n.d., Common Milkweed, Asclepias syriaca, Milkweed family, (Asclepiadaceae),  https://www.illinoiswildflowers.info/weeds/plants/cm_milkweed.html
  2. Berkov, A., 28.October.2010, Plant Talk:  Inside the New York Botanical Garden; Plant Profile:  The Extraordinary Common Milkweed, How Do Insects Feed on this Plant with Sticky White Latex? https://www.nybg.org/blogs/plant-talk/2010/10/science/plant-profile-the-extraordinary-common-milkweed/#:~:text=Plants%20in%20the%20genus%20Asclepias,Asklepios%2C%20the%20ancient%20Greek%20physician.
  3. Bowe, Scott, 11.September.2018, Milkweed is More Than Just a Common Weed, WXPR, https://www.wxpr.org/natural-resources/2018-09-11/milkweed-is-more-than-just-a-common-weed
  4. Nelson, M. and Alfuth, D., 24.February.2021, Milkweed (Ornamental Plants Toxic to Animals), X-number:  XHT1276, https://hort.extension.wisc.edu/articles/milkweed-ornamental-plants-toxic-to-animals/
  5. Taylor, David, n.d., Common Milkweed, (Asclepias syriaca L.), Plant of the Week, https://www.fs.usda.gov/wildflowers/plant-of-the-week/asclepias_syriaca.shtml
  6. Eldredge, E.P., 2015,11,00, Milkweed Pollination Biology, Plant Materials Technical Note NV-58, Natural Resources Conservation Service, https://www.nrcs.usda.gov/plantmaterials/nvpmctn12764.pdf
  7. Betz, R.F., Struven, R.D., Wall, J.E. & Heitler, F.B., 1994, Insect Pollinators 12 Milkweed (Asclepias) Species, T.B. Bragg and J. Stubbendieck (eds.) Proc. Of the Thirteenth North American Prairie Conference. Univ. of Nebraska, Lincoln, NE.
  8. No author, n.d., Monarch Waystation Program, https://monarchwatch.org/waystations/
  9. Geere, Duncan, 2010. August.19, Tiger Moths Scare Bats with Ultrasonic Clicks, Wired, https://www.wired.com/2010/08/moth-jamming/
  10. Holm, Heather, 2017, Bees:  An Identification and Native Plant Forage Guide, Pollination Press LLC
  11. No author, n.d., Ichneumon Wasps, Discover Nature>Field Guide:  Missouri Department of Conservation, https://mdc.mo.gov/discover-nature/field-guide/ichneumon-wasps
  12. No author, n.d., Sand Wasps, Discover Nature>Field Guide:  Missouri Department of Conservation, https://mdc.mo.gov/discover-nature/field-guide/sand-wasps
  13. Berish, Chelsea, n.d., Spined Soldier Bug in Kentucky, ENTFACT-325: SPINED SOLDIER BUG IN KENTUCKY, University of Kentucky Department of Entomology, Martin Gatton College of Agriculture, Food and Environment
Categories
native plants Pollinator gardening

A Summer Cornucopia

Common Milkweed or Asclepias syriaca is a superb Monarch support and a mainstay of Monarch waystations.  But it is so much more.  This plant feeds more than 450 insects at different life stages. Diverse insects consume nectar, sap, leaves, flowers and seeds5.  Admittedly weedy, its lovely blooms are fragrant and enhance any scent garden1,5.

Common Milkweed thrives in full sun and well-drained soils.  Like other “weeds”, it’s not picky about growing conditions.  A. syriaca  grows in clayey, sandy or rocky calcareous soils, loamy soils and high clay or sand soils. 

Asclepias syriaca springs up in disrupted areas.  Human activity disrupts natural areas.  But natural disruptions occur where water rises and falls, for example, along streams and lakes.  

In nature, Common Milkweed is found in moist and dry black soil prairies, sand prairies, sand dunes along lake shores, fields, pastures, abandoned fields, vacant lots and along railroads, fence rows and roadsides. 

Common Milkweed absolutely lives up to its weedy name.  It spreads by seed and by long creeping rhizomes that pop up in unexpected places.  Once established, this plant is extremely difficult to remove. 

These habits are offset by Common Milkweed’s value to insects and pollinators.  It’s best to let it grow where you don’t mind its vigorous and abundant nature—a wild area, a meadow or a prairie garden.

Asclepias syriaca offers a strong erect form in the garden.  The pale, cylindrical central stem supports opposite jade-green leaves.  These leaves range from pale to dark green on top and are pale green with short, dense hair underneath.  Each leaf has a distinctive central vein with small veins spreading to the edges.  

The milky sap, which gives Milkweed its name, oozes whenever part of the plant is broken.  The sap is called a latex and contains 2% latex.  The latex is thick and sticky.  

Most ingeniously, caterpillars will reduce the sap’s flow by taking tiny bites closer to the stem.  The sap leaks out there.  When the caterpillar begins to eat a leaf, there’s less latex at the feeding site.  Thus, less chance the sticky stuff will foul the larva’s mouth2,3.

For humans and other mammals, there are other concerns.  The milky sap contains cardenolides, specifically cardiac glycosides.  Contact with the skin or eyes causes irritation.  If eaten or exposed to mucous membranes, cardiac glycosides can disrupt the nervous system, the kidneys, the muscles (which includes the heart) and the human’s/animal’s acid/base balance3,4,5.  

The monarch and other insects that consume milkweed have turned this to their advantage.  As the caterpillars/insects consume milkweed their bodies store the cardiac glycosides.  If a bird or animal eats them, they taste bitter and can make the predator feel sick.  

Predators soon learn to leave them alone. The orange/black or red/black coloring of milkweed insects signals, “Stay away!  Not good for you!”  The technical term for this warning coloration is ‘aposematic’5.

Milkweed blooms don’t dazzle but flower in 1930’s vintage shades.  The drooping balls of florets are soft and dusky lasting one to one and a half months.  Colors range from greenish white to greenish pink to rosy-pink to purplish-pink to reddish purple.  

Each cluster averages 30 individual florets but can have up to 100. Their sweet, vanilla fragrance drifts from the three to five umbels on each plant.  

Up close, each floret is a fascinating feat of engineering all directed toward an exceptional pollination system.  Each a quarter of an inch across, the florets have five reflexed (bent back) petals and five raised hoods with curved horns.  The hoods have lighter colors than the petals.  

In the center of each floret, is a cylindrical structure formed by two fused stigmas.  It’s called the stigmatic column.  

Between the hoods, are the stigmatic slits.  These slits hold the pollinaria.  Unique structures, pollinaria hold waxy sacs of pollen.  These are transferred instead of the loose, powdery pollen used by most flowers.  Milkweeds and orchids are the only known plants to have them6,7.

The milkweed pollinium (or pollinarium) consist of a blackish-brown oval gland (corpusculum) with a slit, two translator arms hanging from the gland and two pollinial sacs.  Before each sac, a knee bend of approximately 900 occurs in the arm.  This bend enables the rotation of each sac during pollination.

In the milkweeds, the pollinial sac sit inside the stigmatic column and only the corpusculum is visible between the hood structures.  When an insect lands on the flower, one of its legs may slip into the stigmatic slit between two hoods.   As it tries to free itself, the leg moves upward toward the slit in the corpusculum. Bristles in the chamber keep it from going back down.  

Insects must be strong to free themselves.  Large butterflies, predatory wasps and long tongue bees are most likely to remove pollinaria.  Lost legs and dead smaller insects both occur from failed escape attempts.

When a pollinaria is removed, it begins to dry.  The pollinial sacs rotate 90o during drying.  The rotation moves them into the correct position for pollination.  

When the insect lands on another milkweed,  the knee bend (not the corpusculum oval) slides into the space between the hood petals.  The translator arm follows then the rotated pollinial sac.  The pollinial sac slides into a space in the stigmatic column and pollination is completed.  

When the insect continues pulling upward, the translator arm breaks.  The insect keeps the remaining part of the pollinaria.  

It’s also possible to start a chain of pollinaria during this process.  As the broken translator arm slides between the hoods, it can hook the corpusculum slit of this floret’s pollinaria adding a fresh pollinaria to the partial remaining one.  Clumps and chains of all sorts develop this way.  These groups of pollinaria may increase chances of pollination6.7.

Part I, ends here, with the exciting conclusion of a fertilized milkweed.  Part II will continue with photos and information about the insects that use Common Milkweed.  What a crowd it is—including flies, wasps, bees, butterflies, moths, skippers, plant bugs and beneficial insects!

See you next time to discover what Wild Things are in the Garden!

Mary

References

  1. Hilty, J., n.d., Common Milkweed, Asclepias syriaca, Milkweed family, (Asclepiadaceae),  https://www.illinoiswildflowers.info/weeds/plants/cm_milkweed.html
  2. Berkov, A., 28.October.2010, Plant Talk:  Inside the New York Botanical Garden; Plant Profile:  The Extraordinary Common Milkweed, How Do Insects Feed on this Plant with Sticky White Latex? https://www.nybg.org/blogs/plant-talk/2010/10/science/plant-profile-the-extraordinary-common-milkweed/#:~:text=Plants%20in%20the%20genus%20Asclepias,Asklepios%2C%20the%20ancient%20Greek%20physician.
  3. Bowe, Scott, 11.September.2018, Milkweed is More Than Just a Common Weed, WXPR, https://www.wxpr.org/natural-resources/2018-09-11/milkweed-is-more-than-just-a-common-weed
  4. Nelson, M. and Alfuth, D., 24.February.2021, Milkweed (Ornamental Plants Toxic to Animals), X-number:  XHT1276, https://hort.extension.wisc.edu/articles/milkweed-ornamental-plants-toxic-to-animals/
  5. Taylor, David, n.d., Common Milkweed, (Asclepias syriaca L.), Plant of the Week, https://www.fs.usda.gov/wildflowers/plant-of-the-week/asclepias_syriaca.shtml
  6. Eldredge, E.P., 2015,11,00, Milkweed Pollination Biology, Plant Materials Technical Note NV-58, Natural Resources Conservation Service, https://www.nrcs.usda.gov/plantmaterials/nvpmctn12764.pdf
  7. Betz, R.F., Struven, R.D., Wall, J.E. & Heitler, F.B., 1994, Insect Pollinators 12 Milkweed (Asclepias) Species, T.B. Bragg and J. Stubbendieck (eds.) Proc. Of the Thirteenth North American Prairie Conference. Univ. of Nebraska, Lincoln, NE.

Categories
native plants Pollinator gardening

Sparks in the Garden

Every year in the early Fall, a glittering cloud of insects surrounds the arching stems of Solidago rugosa ‘Fireworks’.  Butterflies, moths, skippers, bees, wasps, beetles, beneficial insects, and flies all flock to this goldenrod for nectar, pollen and to use it as a larval host.  This feast helps prepare them for the cold months of winter.

The twinkling yellow flowers of ‘Fireworks’ goldenrod pop open along stems up to 18” long!  Held above the foliage, these stems resemble fireworks and give the plant its name.  Pompom blooms are tightly packed along the stems. Each one is about 1/8th inch in diameter.  The anthers are held above the stigmas and bright yellow ray flowers form the outer ring.  Peak bloom lasts two to three weeks.

Medium to dark green leaves grow alternately and are three to six inches long.  They range from ovate to lanceolate and their edges are toothed.  The deeply sunken veins in the leaves causing a wrinkled look. This feature gives them the name rugosa or wrinkled.  In fact, a common name for the native Solidago rugosa is Wrinkle-Leaved Goldenrod.

Solidago rugosa ‘Fireworks’ is a charming goldenrod cultivar.  Well-behaved, it sports abundant bloom for a grand show in the garden.  An erect plant, it forms dense clumps with slowly spreading rhizomes.  It grows three to four feet tall.  Spreading from two to three feet, ‘Fireworks’ will reseed if happy.  Space plants one to three feet apart.  

‘Fireworks’ thrives in zones four to eight.  It enjoys moist, well-drained soils although it can tolerate periods of drought or wet soil.  Highly adaptable to different soils, this goldenrod grows in clay, loam (silt), and sand as well as acid to neutral conditions. My plants have not been bothered by deer or rabbits.  It can withstand both heat and humidity. 

The genus Solidago, like Symphyotrichum, is an essential part of wildlife habitat, a keystone species.  In recent years, people have become interested in keystone species of all types.  A keystone species is one so crucial that the ecosystem will collapse without it.

How does this work with plants?  Key plants are native plants that are part of the local food web.  They play a role as a general or specific support for insects.  The general group are the 14% of native plants that support 90% of butterfly and moth Lepidoptera species.1  The specific group are the 40% of native plants that produce pollen for the 15% to 60% of North American native bee pollen specialists.1  Both these groups are listed in the Keystone Plants by Ecoregion from the National Wildlife Federation.  According to this information, Solidago sustains 104 species of caterpillars and 42 different specialist bees.2  (I have used the Eastern Temperate Forest list since this is my region.)  In addition to these categories, 145 different wasp species forage on Solidago.3

So, goldenrod offers abundant food at the end of the year, how is this valuable?  Fall is when next year’s insect generation is established.  Whether it’s healthy adults, well fed caterpillars or full provisions in nests, the foundations are laid with Autumn food harvest.  Goldenrod is one vital resource.

Different insects have different strategies for surviving the winter.  In the next few paragraphs, I’ll talk about what the pollinators do over the winter and where they might be.  Bumblebee and honeybee queens take mating flights in the late summer or fall.  Male bumblebees take advantage of nectar from Solidago ‘Fireworks’ to fuel up before pursuing their queen. When they’ve mated, the queens find a safe location to overwinter.  Some bumblebee queens hibernate in leaf litter and others burrow underground.4

Honeybee queens return to the hive.  During the winter, the honeybees form a ball in the hive.  If they become cold, they will vibrate for warmth.  The queen stays near the center of the mass.  Any resources gathered in the fall, are converted into honey, and used to help the honeybees survive the winter.5

Native bees overwinter as young in their nests.4  Active native bee queens use the resources from goldenrods to supply their nests.  Like Symphyotrichum, Solidago has numerous bee specialists including:  Andrena (Callandrena) asteris, A. (Callandrena) braceata,  A. (Callandrena) simplex, Andrena (Cnemidandrena) hirtcincta, Andrena (Cnemidandrena) canadensis, Colletes simulans, Colletes solidaginis, Perdita (Perdita) octomaculata and Melissodes (Eumelissodes) fumosus.

Where are their nests?  70% of native bees nest underground!  Now is not the time to start digging.  Others nest in old beetle burrows and other holes in dead wood and still others in hollow stems.4  It’s better to wait until spring to cut back dead stems and clean up dead wood.

Solidago rugosa ‘Fireworks’ attracts numerous native wasps.  Indeed, unlike asters, I find wasps visiting my ‘Fireworks’ goldenrod in equal numbers with the bees.  These wasps serve as beneficial insects preying on or parasitizing pests that damage plants.  They also contribute to pollination as they drink nectar and, occasionally, eat pollen.  Native wasps spend the winter in different ways:  some as mated females called foundresses, some as young and some we don’t know yet.  The foundresses find dry, warm spots to hide in.  Other nesting locations are similar to bees including stems, wood, underground and old nests built by other wasps or bees.3

Many flies visit ‘Fireworks’ goldenrod to drink nectar and, incidentally, pollinate the flowers. The larval stage of some Tachinid and Syrphid flies are beneficial insects. Tachinid flies parasitize leaf eating insects. They over winter in the larval or pupal stage often in the shell of their host. The larvae or pupae can be found in piles of leaves or bush or burrowed into the soil.

Syrphid fly larva are excellent early and late season predators. They consume dozens of aphids each day. Most spend the winter as pupae or larvae in dead leaves or piles of brush.

Butterflies use goldenrod for nectar.  Monarchs fuel up for their migration and other butterflies build fat stores to hibernate as adults.  Not all butterflies overwinter as adults,  they can spend the cold months as eggs, caterpillar, chrysalis, or adults depending on the species.  The eggs are laid close to a spring food source.  Caterpillars deliberately hid in curled leaves, soil or under rocks for protection.  If becoming a chrysalis, the caterpillar will choose a protected location, for instance, under an overhang or deep in a shrub.  Adult butterflies and moths are very diverse when hiding.  Spaces under bark, crevices in trees, cracks in rock and the fall leaves all host butterflies and moths.6

Solidago serves as a larval host for 104 butterfly and moth caterpillars.  One unusual moth is the Wavy-Lined Emerald.  The caterpillar has a fascinating adaptation.  It decorates itself with the leaves or flowers from its host plant.  This camouflage hides it from predators.  The twirler moths (Gelechiidae), Geometer moths, Owlet Moths (Noctuidae), and Tortrix Moths also use Solidago.

The take home for today: Leaves are not Litter!  Stems Stand Tall!  Don’t Do that Digging!

Just take a rest, drink some cider, and enjoy those Fall colors!

References:

  1. Keystone Plants by Ecoregion, The National Wildlife Federation, https://www.nwf.org/Garden-for-Wildlife/About/Native-Plants/keystone-plants-by-ecoregion
  2. National Wildlife Federation, Gardening for Wildlife, Keystone Native Plants Eastern Temperate Forests – Ecoregion 8, https://www.nwf.org/-/media/Documents/PDFs/Garden-for-Wildlife/Keystone-Plants/NWF-GFW-keystone-plant-list-ecoregion-8-eastern-temperate-forests.ashx?la=en&hash=1E180E2E5F2B06EB9ADF28882353B3BC7B3B247D
  3. Holm, H., 2021 Wasps:  Their Biology, Diversity, and Role as Beneficial Insects and Pollinators of Native Plants, Minnetonka, MN, Pollination Press LLC.
  4. Morris, S. (2018, October 10). Where Do Pollinators Go In The Winter? Xerces Society for Invertebrate Conservation.  https://xerces.org/blog/where-do-pollinators-go-in-winter#:~:text=Most%20native%20bee%20species%20will,help%20to%20survive%20until%20spring.
  5. Hogeback, J. Where Do Honeybees Go In The Winter?  Britannica.  https://www.britannica.com/story/where-do-honeybees-go-in-the-winter
  6. Grisak, A. (2022, November 04). How Does A Butterfly Survive Winter? Birds & Blooms. https://www.birdsandblooms.com/gardening/attracting-butterflies/butterflies-in-winter/
Categories
native plants Pollinator gardening

THE GARDEN BY CANDLELIGHT

Okay, not actual candlelight, but the ethereal candelabra blooms of Veronicastrum virginicum, Culver’s Root.  This striking, upright plant provides a strong vertical accent in any garden.  It’s long, tapered flower spikes attract pollinators of all kinds while dark green whorls of leaves provide plenty of visual interest.

Growing in zones 3 to 8, this plant stretches from four to seven feet and spreads between two to four feet.  Culver’s Root grows in medium to wet, well-drained soils.  It tolerates standing water for a short time and thrives in rain gardens.  Culver’s Root accepts full sun to light shade and is suited to growing at the woodland’s edge.  In very warm zones, it enjoys afternoon shade.  

Culver’s Root’s flowers unfold slowly in mid to late summer.  Here in zone 5b, it starts in mid-July and continues to the end of August.  You can deadhead to encourage rebloom.  

The flower color varies slightly with the location.  Primarily white, the blooms can have tones of very pale pink, lavender or blue.  The blossoms are most often described as candelabra-like with four or more in a whorl at the top of each stem.  In mature plants, flower spikes can be 8” in length!  

Culver’s Root tends to flop without support especially in shadier areas.  I’ve used a peony ring with internal supports.  The deer have also trimmed my plant in mid-June by about one-third to one-half.  The pruning helped and more flowers formed at each cut.  Culver’s Root won’t grow to full height after being cut back. 

Its leaf structure is unusual and offers a contrast to surrounding plants.  The leaves are whorled in groups of three to seven.  Each leaf is lance shaped with slight serrations and attached directly to the stem (sessile) or nearly so.  They can be up to 6” long and 1.5” wide.  The long stems and whorled leaves give the plant an upright, medium texture.  Culver’s Root is not aggressive although it can self-seed.  Some good companion plants include blazing star, monarda, milkweed, rattlesnake master, goldenrod, and asters.

V. virginicum has successfully entered the world of horticulture and numerous nativars exist.  These nativars have been bred to prevent flopping and to bring more color to the flowers.  Some are more compact to fit in small gardens.  Here is a sampling of what’s available:  ‘Fascination’, 5’ tall, 2’ width, lavender bloom, ‘Red Arrow’, 3-4’ tall, 2-3’ width, purple bloom, ‘Album’, 3-4’ tall, 3-4’ width, white bloom, and ‘Cupid’, 2-3’ tall, 1-2’ width, purple.  Like the native plant, all these nativars can grow in zones 3 to 8. 

Culver’s Root feeds native bees, honeybees, and beneficial insects.  A range of native bees visit it including short and long tongued bees.  V. virginicum begins bloom by protruding its anthers outside the bud.  Small bees take advantage of this by collecting pollen. These pollinators include Hylaeus (yellow-faced bees).

Hylaeus or yellow-faced bees are one of the most recognizable small bees.  Mostly black, they have yellow or white markings on their faces.  These marking make them identifiable as Hylaeus although species determination can be tricky.  Yellow-faced bees grow from 5 mm (0.2”) to 7 mm (0.27”).  They nest in existing hollow cavities primarily in hollow stems or holes in wood. Some have been known to nest in stone.  Hylaeus line their nests with a silk or cellophane-like substance produced by the salivary gland.  The bee uses her bilobed tongue to paint on the secretions.  The lining is waterproof and protects the young from bacteria.  Chewed stem pith mixed with saliva is used for cell divisions and salivary gland secretions seal the completed nest.

One fascinating fact, yellow-faced bees are practically hairless.  Hylaeus don’t have any scopa or specialized hairs dedicated to holding pollen like other bees.  They also have short tongues and so can’t reach deeply into flowers.  These bees use their slender bodies to work their way into flowers to reach nectar and pollen.  They also chew on anthers to extract pollen.  Then Hylaeus swallow the nectar and pollen and hold it in their crop.  The crop is a sac separate from the stomach.  This fluid mixture is regurgitated and left for the larva to eat. 

Another fun fact, yellow-faced bees occur all over the world.  However, Hawaii is known for having 63 different species.  The yellow-faced bee is the only bee native there.  All the species found there are unique to Hawaii.

Lasioglossum (small sweat bees) visit Culver’s root and collect pollen and nectar. They use the hair or scopae on the hind femur and tibia to hold the pollen as well as the bottom of their abdomen.

Once the flowers opens larger visitor arrive including bumblebees (Bombus)

and Leaf-Cutter bees (Megachile)

and Long Horned bees (Melissodes). 

Mason bees (Osmia) stop at V. virginicum to collect resources.

Large and small carpenter bees (Xylocopa and Ceratina) also gather nectar and pollen from Culver’s Root.  

This is also a plant for beekeepers.  Honeybees enjoy V. virginicum when they can find it.  I’ve often seen them gathering nectar from this plant in my garden.

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The sphecid and the potter wasps also benefit from the flowers.  They gather nectar to support them while building and filling their nests. I often see the thread-waisted Mexican Grass-carrying wasp (discussed in “White Goes With Everything”, https://wildthingsinthe.garden/2023/05/31/white-goes-with-everything/) on this plant.

These groups of scary insects look nothing like our sweet fluffy bumblebees.  Sphecid wasps resemble nightmare creations with bizarre tiny waists, long thin legs, and triangular heads.  The vespid wasps, which include the potter wasp Eumenes fraternas, can resemble sphecid wasps.   Sadly, they can also look like yellowjackets, hornets and paper wasps who share their family.  Yet when I meet these wasps in the garden, they’re gentle and shy.  

Today, let’s talk about Eumenes fraternas. This wasp is in Vespidae family, subfamily Eumeninae, also called potter and mason wasps.  Eumenes fraternas is a potter wasp that regularly visits the Culver’s root in my garden.  She creates her nest using soil and water.  This wasp collects, mixes, and shapes her mud until she completes a small pot with a flared rim.  The nest is built on a large leaf, sturdy stem, or a home/structure.

Then, the wasp lays a single egg fastening it to the top of the pot with a silk-like thread.  The nest pot is provisioned with several caterpillars.  E. fraternas preys on cankerworms or inchworms.  The potter wasps frequently hunt moth larva in the Geometridae family.  Geometer caterpillars are often pests of native trees eating large amounts of leaves, in some cases, stripping them.

Like other solitary pollinators,  E. fraternas is entirely responsible for her eggs.  It is in her best interest not to sting.  I have found these solitary wasps to be quite cautious.  This holds true for the thread-waisted wasps in my garden and the Mexican Grass-carrying wasp.  If I bump a plant, they’ll fly away while bumblebees persistently keep feeding.  Still, they can sting if handle roughly.

Thank you so much for joining me!  I hope you enjoyed reading about Veronicastrum virginicum, Culver’s root, and consider adding it to your garden. Please let me know what you think of the post and tell me what’s going on it your garden by leaving a comment!

Many Thanks!

Mary