Many of our great botanical gardens in the United States produce and publish research of value to home gardeners and landscape professionals. The Chicago Botanic Garden’s “Plant Evaluation Notes” is one example. These reports can be very helpful in deciding which plants, particularly cultivars, to include in a landscape (with the caveat below).
Keep in mind that while straight species native plants will provide the greatest genetic diversity in a landscape, cultivars can be very useful when size, disease susceptibility, and plant availability, among other issues, may be a concern.
The Chicago Botanic Garden’s report “A Comparative Study of Joe-Pye Weeds and Their Relatives,” examines some of our great later-blooming nectar plants of the Eastern half of the U.S. With recent changes in botanical names, this can be a difficult group to keep track of. Many plants that used to be Eupatorium have been reclassified as Eutrochium, Conoclinium and Ageratina. Fortunately or unfortunately, many growers and nurseries continue to use the old names. Be prepared to encounter both.
The report examines 25 native plants and native cultivars, and one exotic species. It’s unclear why one exotic plant crept into the mix, but it is not included here, since our focus is on native plants. Joe-Pye Weeds and their cousins are important nectar plants for many insects. You will see native bees, honey bees, butterflies and other beneficial insects utilizing these valuable native plants. Keep the plants standing through fall and winter to make any seeds available to seed-eating birds.
The goal of the Chicago Botanic Garden study was to identify outstanding plants for Midwestern gardens. Many of the conclusions will apply to different regions, but note that the study plots had a relatively high soil pH of 7.4 and the plants were grown in well-drained, clay-loam soil with the addition of composted leaves.
Plants were evaluated for their adaptability to soil and environmental conditions, disease and pest issues, winter hardiness and ornamental qualities. As always, beauty is in the eye of the beholder. While some plants may have received lower ratings, they may perform an important ecological function. White Snakeroot (Ageratina altissima) received a lowly two star (poor) rating in the study, but I find this plant to excel in dry shade in my New York landscape, where not much else wants to grow.
Since biodiversity is the key to a healthy ecosystem, plant diversely with regional native plants, and that includes some of the lower-rated plants, which may still be important ecologically. Where clients, spouses, or neighbors are a concern, put the gorgeous plants front and center, still utilizing the “Plain Janes.”
There are other useful plants which were not covered in the study, including one of my favorites, Common Boneset, (Eupatorium perfoliatum), which excels at providing bees with late season nectar while growing out of the cracks by the edge of my driveway in full sun. Now, that’s a well-adapted plant!
I encourage you to identify the Joe-Pye Weeds and related plants that are appropriate for your region. The Lady Bird Johnson Wildflower Center plant database and Biota of North America are two good places to start.
Here are the results of the Chicago Botanic Garden study:
Five Stars (Excellent)
- Ageratina altissima ‘Chocolate’ (White Snakeroot cultivar)
- Eutrochium dubium ‘Little Joe (Coastal Plain Joe-Pye Weed cultivar)
- Eutrochium fistulosum ‘Carin’ (Hollow Joe-Pye Weed cultivar)
- Eutrochium fistulosum f. albidum ‘Bartered Bride’ (Hollow Joe-Pye Weed, white form cultivar)
Four Stars (Good)
- Conoclinium coelestinum (Hardy Ageratum)
- Conoclinium coelestinum ‘Album’ (Hardy Ageratum cultivar)
- Conoclinium coelestinum ‘Cori’ (Hardy Ageratum cultivar)
- Eupatorium serotinum (Late Boneset)
- Eutrochium dubium ‘Baby Joe’ (Coastal Plain Joe-Pye Weed cultivar)
- Eutrochium maculatum ‘Phantom’ (Spotted Joe-Pye Weed cultivar)
- Eutrochium maculatum ‘Purple Bush’ (Spotted Joe-Pye Weed cultivar)
- Eutrochum purpureum (Sweet-Scented Joe-Pye Weed)
Three Stars (Fair)
- Ageratina aromatica ‘Joicus Variegated’ (Lesser Snakeroot cultivar)
- Eupatorium hyssopifolium (Boneset)
- Eutrochium dubium (Coastal Plain Joe-Pye Weed)
- Eutrochium fistulosum ‘Selection’ (Hollow Joe-Pye Weed cultivar)
- Eutrochium fistulosum f. albidum ‘Ivory Tower’ (Hollow Joe-Pye Weed, white form cultivar)
- Eutrochium maculatum (Spotted Joe-Pye Weed)
- Eutrochium maculatum ‘Atropurpureum’ (Spotted Joe-Pye Weed cultivar)
- Eutrochium maculatum ‘Gateway’ (Spotted Joe-Pye Weed cultivar)
- Eutrochium maculatum ‘Glutball’ (Spotted Joe-Pye Weed cultivar)
- Eutrochium maculatum ‘Little Red’ (Spotted Joe-Pye Weed cultivar)
- Eutrochium maculatum ‘Riesenschirm’ (Spotted Joe-Pye Weed cultivar)
Two Stars (Poor)
- Ageratina altissima (White Snakeroot)
- Eupatorium rotundifolium (Round-Leaved Thoroughwort)
One Star (Very Poor)
Find a spot in your landscape for some of theses many Joe-Pye Weeds and their relatives. Watch my short video on Joe-Pye Weed on YouTube. And, check out other useful studies from the Chicago Botanic Garden.
Feed a bee, plant a Joe-Pye Weed from Kim Eierman at EcoBeneficial!
Photo: Eutrochium dubium ‘Little Joe’ With a Hungry Bee