Taxonomical Classification, Botany of Joe-Pye Weed
Plant taxonomy places the various types of this plant in the genus, Eupatorium (you will also encounter the names Eupatoriadelphus and Eutrochium in your research, thanks to taxonomic changes over the years). This article deals most specifically with the kind known as "spotted Joe-Pye weed" (Eupatorium maculatum).
It is a member of the aster family.
Spotted Joe-Pye weed is a "weed" only in the sense that it is a wild plant (in North America). "Wildflower" would be a better name for a plant with such an attractive, mauve flower and imposing presence (up to 6 feet tall). Despite the specific epithet, maculatum (meaning "spotted"; see below), the stems often come in a solid purple that offers an even more striking look. These sturdy stems make E. maculatum a good cut flower. Its flower heads are flattish; its leaves grow in whorls and are lance-shaped. E. maculatum eventually spreads to form a dense stand.
A wet area in the landscape often presents a challenge to the homeowner: Many plants will not perform well there. At home in wetlands in the wild, spotted Joe-Pye weeds are a good choice when you need plants for wet soils. They are plants that attract butterflies, including tiger swallowtails and black swallowtails.
Planting Zones, Growing Conditions
Uses in Landscaping
At the center of a planting circle surrounded by shorter plants, this highly architectural specimen can serve as a focal point. In addition to its beauty, the plant has another selling point: It is a late bloomer, flowering in late summer and into autumn, well after most other plants in its native region have ceased flowering. As such, it can be a useful plant to grow if you wish to stagger blooming periods in your yard, as you should be doing if your goal is landscaping for the four seasons. Finally, given its native status in eastern North America, it is a natural choice for native-plant lovers looking to fill a space in a native perennial sun garden.
Types of Joe-Pye Weed Plants
Besides spotted Joe-Pye weed (E. maculatum), other types native to North America are:
- Hollow Joe-Pye weed (E. fistulosum)
- Eastern or "three-nerved" Joe-Pye weed (E. dubium)
- Sweet Joe-Pye weed (E. purpureum)
Cultivars of Eupatorium are also available (see below).
Plant Care Recommendations
Cut the prior year's stalks down to the ground in early spring. New shoots will push up from the system of rhizomes underground. The plant can be aggressive; if you wish to keep it in check, you will have to contain the spread of the rhizomes either by cutting them or by blocking their progress with bamboo barriers or the like.
Cultivars such as Eupatorium maculatum 'Gateway' are better-behaved. Pinch it back in late spring to keep the plant more compact.
If you are happy with this aggressive plant and wish to increase your supply of it and grow it in an additional spot in the landscape, undertake springtime division.
Cultivars, Meaning Behind the Names
Spotted Joe-Pye weed is a wildflower, but cultivars of Eupatorium are also available. Besides the mauve color shown in the picture, some folks plant white-flowering varieties. The existence of white-colored types should not surprise those familiar with the related wildflowers, snakeroot (E. rugosum) and boneset (E. perfoliatum), both of which bloom in white. E. rugosum 'Chocolate' has white flowers; its cultivar name derives from the dark splotches in its foliage.
In The Book of Perennials (p.
150), Alfred C. Hottes states that the genus Eupatorium was named "for Mithridates Eupator, King of Pontus, who discovered a species to be an antidote against poison" (others say that the species in question was, itself, poisonous, and that Mithridates consumed it in small doses to build up a tolerance to it). On the same page Hottes notes that the common name for E. maculatum, etc. "is derived from Joe Pye, an Indian herb doctor of Pilgrim days in Massachusetts. He is reputed to have cured typhus fever from a decoction of the plant."
Meanwhile, the species name, maculatum is Latin for "spotted" and refers to the fact that spotted Joe-Pye weed often bears purplish flecks on its stems.