Ask A Master Gardener – Giant Joe Pye Weed

Authored by: Carol Shirk

If you are looking for a stately, eye-catching, late-summer to fall blooming plant for the back of your flower gardens, look no further than Joe Pye Weed.  Do not be deterred by the name, for this pollinator-magnet is no weed.

Photo Credit: C. Shirk

There are several species of Joe Pye Weed (Eupatorium) that grow in Wisconsin gardens.  Sweet Joe Pye Weed (Eutrochium purpureum) is a native perennial that grows 4–7 feet tall on strong green stems.  Tall Joe Pye Weed (Eupatorium fistulosum), another native perennial, will be about the same size, and Spotted Joe Pye Weed (Eupatorium maculatum), the baby of the bunch, is 3–5 feet tall on purple spotted stems.

Booming in late summer with large clusters of pink/purple flower heads, the dramatic Joe Pye Weed blooms persist for at least a month until they are replaced by tiny seeds attached to tufts of hair that are dispersed by the wind.

History, supported by research from University of Michigan, indicates this plant derived its name from the Christianized name of a Mohican Native American botanist, Joe Pye.  He shared his traditional herbal medicine methods with the settlers in the Massachusetts area, including the use of this plant for curing fevers.

Joe Pye Weed will grow best in full sun (although Sweet Joe Pye Weed tolerates more shade) and nearly any type of soil, although rich well-drained soil will give best results.  It prefers more moist conditions, but once established will tolerate even short periods of drought. It is difficult, but not impossible to start Joe Pye Weed from seeds. Scatter the seeds in the fall, as they require a period of cold stratification before germination.  An easier option is to start with root divisions or by purchasing a nursery plant.  Plant these in the spring as soon as frost danger has passed.  Keep in mind that this is a substantial plant and it will need sufficient space to grow; do not overcrowd it.  One of the very few problems encountered with Joe Pye Weed is powdery mildew.  This can be kept at bay by providing adequate air flow between plants.

Because of its height, Joe Pye Weed will do best at the back of a garden.  Fear not, it will still garner plenty of attention as it towers above most other plants.  The showy cluster of flowers are attractive by themselves, but they will buzz and flutter with pollinators, increasing the beautiful display.  Monarch, admiral, and swallowtail butterflies are frequent visitors.  Bumble bees (including the threatened Rusty Patched Bumble Bee), cuckoo bees, digger bees, and leaf-cutter bees all appreciate the blooms.

While pollinators are having a party on the blooms, deer, rabbits, and other grazers seem to have no interest in these plants.  The seeds will be a food source for birds in the fall.

While it is recommended that most native plants be left until spring for clean-up, Joe Pye Weed will be an exception. It is to cut down the plants once the frost has killed the flowers and winter threatens.  It will quickly spread by sending the seeds abroad and one way to keep it contained is to take it down in the fall.  In addition, it blooms on new season growth.  Waiting too long in the spring to prune can impair the new blooms.

Carol Shirk

Certified Master Gardener


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