• Eupatorium dubium, E. fistulosum, E. maculatum, E. purpureum, E. steelei
• Family Compositae
• Hardy perennial
You may need a botanist to sort out which one is which, but any of the Joe-Pye weeds can add a lively splash of color to the late-summer garden. Now grown mainly for their landscape value, these stately natives were once utilized extensively as medicinal herbs.
The genus Eupatorium comprises about 40 species of mostly perennial, chiefly tropical herbs and shrubs. The genus name honors Mithradates VI Eupator, king of Pontus (an ancient country in northern Anatolia in Asia Minor), who died in 63 b.c. The king is remembered among botanists and toxicologists for having been “one of the first to study intensively the art of poisoning and the preparation of antidotes.” He is said to have immunized himself against poison by taking increasingly large, nonlethal doses. One plant he experimented with is supposed to have been a member of the genus.
About five species of North American eupatoriums are known as Joe-Pye weeds. The origin of the common name is uncertain. The most prevalent theory holds that it refers to a Colonial-era Native American named Joe Pye, who is said to have used one of the species to cure typhus. Another is that Joe Pye was a nineteenth-century white “Indian theme promoter” who used the root of one of the species to induce sweating in cases of typhus. The earliest use of this name dates to 1810–1820.
The Joe-Pye weeds are all tall, erect herbs with leaves arranged in whorls on the stem. The flower heads are generally large, domed or flat-topped clusters of small purplish tubular disk flowers. The species differ in leaf shape and veining; convexity of the flower cluster; number of flowers per head; and hairiness, color, and hollowness of the stem. All bloom from July to September. They hybridize widely in nature, making identification a challenge even for botanists.
Spotted Joe-Pye weed (E. maculatum) has stout, speckled or purplish stems 2 to 6 feet tall. The sharp-toothed, lance-shaped leaves are in whorls of four to five. Purple to pale lavender flowers are borne in flat-topped clusters. The species is found in moist places, especially in limy soils, mainly in eastern North America but in the north as far west as British Columbia.
Sweet Joe-Pye weed (E. purpureum), also called gravel-root or queen-of-the-meadow, may grow as tall as 12 feet. The stem is green except at the leaf nodes, where it is purple. Like those of spotted Joe-Pye weed, the leaves are sharply toothed but generally come in whorls of three or four. They emit a vanilla odor when bruised. Its pale pinkish or purplish flowers are held in rounded clusters. It is found in thickets and open woods in eastern North America.
Hollow-stemmed Joe-Pye weed (E. fistulosum—fistulosum means “hollow” in Latin) is very similar to sweet Joe-Pye weed. The stem is usually purplish throughout and has a distinct bloom like the surface of a blueberry. Its distinguishing feature, however, is its large central cavity; sweet Joe-Pye weed usually has a solid stem or only a small cavity. The leaves of hollow-stemmed Joe-Pye weed are mostly in fours to sevens and are narrowly elliptic with more rounded teeth than the two preceding species. The flowers are a bright pink-purple. It is found in bottomlands and moist woods in eastern North America.
Steele’s Joe-Pye weed (E. steelei) is much like sweet Joe-Pye weed, but its stems and leaves are hairier and broader than those of the latter. It is found in wooded areas in the Appalachian Mountains.
Three-nerved Joe-Pye weed (E. dubium—dubium is Latin for “doubtful”) is so called because its leaves have two large veins that arise near the base of the midvein. The leaves are ovate, thick, and somewhat bumpy, and they occur in threes or fours. The purple-speckled stems may grow to 3 1/2 feet tall. The flower head is convex and bears purple flowers. This species occurs in moist, acid soil near the Atlantic Coast from Nova Scotia to South Carolina.
Medicinal Uses For Joe-Pye Weed
Native Americans, and later, white settlers, made much use of Joe-Pye weed: they most likely used whichever species was available. Teas of the roots or tops were used as a diuretic, as well as for rheumatism, gout, fevers, diarrhea, respiratory disorders, and even impotence. (Gravel-root refers to the kidney or bladder stones that E. purpureum was supposed to eliminate.) Modern science has not confirmed their efficacy.
Landscape Uses For Joe-Pye Weed
Today, we’re unlikely to grow Joe-Pye weeds for their medicinal qualities, but they have a place in gardens—especially large ones—in USDA Zones 3 to 8 (perhaps to Zone 10 where summers are not too humid). Europeans have prized them and developed a number of dazzling cultivars. ‘Gateway’ (variously attributed to E. maculatum or E. fistulosum) has 8-foot-tall, wine red stems and dark pink or purple vanilla-scented flowers in rounded clusters. It is readily available at local nurseries or by mail order. E. f. ‘Alba’, ‘Bartered Bride’, and ‘Future Music’ all have pure white flowers. ‘Selection’ is a 5- to 6-foot-tall compact form of E. fistulosum with mauve flowers. E. m. ‘Atropurpureum’ is a 6-foot form with purplish stalks and leaf veins and rose pink flower heads.
All the Joe-Pye weeds attract butterflies and bumblebees, and all make good cut flowers. They are superlative grown at the back of the border with other late-summer companions such as goldenrods and asters.
Growing Joe-Pye Weed
If you’re starting with a plant or plants, select a site with moist soil in full sun. They will tolerate light shade but tend to grow taller and floppier there. Plants can grow 4 to 6 feet across, so leave plenty of room between them and their neighbors.
To start seeds indoors, just press them into the potting medium; do not cover. Transplant seedlings to larger pots. Gradually harden them off before transplanting them to the garden.
• Arrowhead Alpines, PO Box 857, Fowlerville, MI 48836. Seed list $2. Eupatorium fistulosum, E. f. ‘Atropurpureum’, E. maculatum, E. purpureum. Seeds.
• Goodwin Creek Gardens, PO Box 83, Williams, OR 97544. Catalog $1. E. purpureum. Plants.
• Milaeger’s Gardens, 4838 Douglas Ave., Racine, WI 53402-2498. Catalog $1. E. ‘Bartered Bride’, ‘Gateway’. Plants.
• Niche Gardens, 1111 Dawson Rd., Chapel Hill, NC 27516. Catalog $3. E. fistulosum, E. f. ‘Selection’. Plants.
• Richters, Goodwood, ON L0C 1A0, Canada. Catalog free. E. purpureum. Seeds, dried root.
• Weiss Brothers Perennial Nursery, 11690 Colfax Hwy., Grass Valley, CA 95945. Catalog free. E. m. ‘Atropurpureum’. Plants.