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joe pye weed seed collection

The best stands of E. purpureum are north of our North Fire Break, just before the steep drop off into the oak woodland. I used the Kawasaki Mule to get in there, and it was an enjoyable day, quiet and peaceful. I got two buckets full of seed heads.

Yesterday I spent an hour or so collecting woodland Joe Pye weed ( Eupatorium purpureum ). This species is relatively similar to the wetland Joe Pye weed ( E. maculatum ), but less colorful and better adapted to woodland areas. It is a strikingly tall species that has become established in those parts of our savannas which have more closed canopy (50% or even a bit more).

Although the flower heads seem fairly dry, they still need to be dried a few days by spreading them out on a tarp. Once dry, the seeds must be cleaned before using. It is fairly easy to clean the seeds. Just put the flower heads on top of a piece of fairly course screening (available from a hardware store) and scrape them back and forth. The seeds fall through, and the empty stems can be thrown away. Store the seeds in a dry place in a grocery bag until time to plant.

While I was seed collecting, I was also keeping my eye out for small buckthorn that needed spritzing or basal barking. Fortunately, the buckthorns were fairly scattered here, and I proably only treated a couple dozen plants. I carried a spray bottle in my belt pack. We’ll be back in this area in the winter for more extensive buckthorn work. Hopefully, this will be a low snow year so that we can get some work done!

Division: Mature plants are best divided in the fall after they go dormant. Each plant will have numerous stems arising from a wide crown with a fibrous root system. To divide the crown, place a sharp shovel between the stems and force it downward to cut, and then separate pieces of stems along with their portion of the crown and roots. Replant the separated piece at the same depth as it was originally, and then mulch and water to settle the soil.

Joe-Pye weed (Eutrochium purpureum var. purpureum) flowers are fragrant and attract many pollinating insects, especially butterflies.
Joey Williamson, ©2017 HGIC, Clemson Extension

Joe-Pye weeds (Eutrochium spp.) are early fall blooming wildflowers that colonize roadside ditches in sunny, moist sites. These native perennial plants grow to 4 – 6 feet tall and bloom along with goldenrods (Solidago spp.), ironweeds (Veronica fasciculata), and our native grasses to make a beautiful autumn display. The flowers are mildly fragrant and very attractive to butterflies and other beneficial insects.

Propagation

Powdery mildew (the grayish-white fungal coating on the foliage) is a common problem on many Joe-Pye weeds, such as on this roadside Eutrochium purpureum var. purpureum.
Joey Williamson, ©2017 HGIC, Clemson Extension

Joe-Pye weeds are relatively free of disease or insect pest problems, except for powdery mildew on the foliage. This is especially more of a problem on the straight species, i.e., when it is not an improved cultivar. Powdery mildew reduces the photosynthetic ability of the foliage (i.e., the ability to manufacture carbohydrates), as well as causes the leaves to desiccate (i.e., to dry up and die). Several fungicides will control powdery mildew on Joe-Pye weed, as well as on other perennials. For examples of both cultural controls that reduce disease incidence and fungicides with specific products, please see HGIC 2049, Powdery Mildew.

Although not all Eutrochium species are naturally found in South Carolina, all of these species should grow well over the majority of the state, and improved cultivars of the first four species listed are also found in the nursery trade. Joe-Pye weeds are cold hardy plants and grow well in USDA Zones 4 to 8.

Joe-Pye weed was originally classified in the genus Eupatorium but was recently (2000) placed into the genus Eutrochium. Five species of Eutrochium naturally occur in the Southeast, and all are referred to as Joe-Pye weeds: