Eutrochium spp.
Joe-Pye weeds
Overview
Eutrochium spp. is a genus of five species of tall herbaceous perennials in the family Asteraceae, native to eastern and central North America and long known as Joe-Pye weeds. Segregated from Eupatorium spp., the genus is distinguished by leaves arranged in whorls of three to seven around stout, often purple-flecked stems. Plants rise 4 to 10 feet (1.2 to 3 m) tall and form upright clumps 2 to 4 feet (60 to 120 cm) wide. From midsummer into autumn the stems are topped by large, domed to elongated clusters of small mauve-pink to dusky purple flower heads, each cluster spanning 4 to 18 inches (10 to 45 cm). The flowers carry a faint vanilla scent and are followed by tufted seed heads that persist into winter. The lance-shaped leaves are 4 to 12 inches (10 to 30 cm) long with toothed margins. The genus grows naturally in moist meadows, streambanks, and wet thickets and wilts quickly in dry soil. All parts contain pyrrolizidine alkaloids that are toxic if eaten.
Native Range
Eutrochium spp. is native to eastern and central North America, ranging from southern Canada through the eastern and central United States. Species such as E. maculatum extend across the northern states, while E. fistulosum and E. purpureum occur through the eastern woodlands and into the southeast.Suggested Uses
Joe-Pye weeds are grown at the back of borders, in rain gardens, and in native and pollinator plantings, spaced 24 to 36 inches (60 to 90 cm) apart. The late-summer flowers attract butterflies and bees in large numbers. The tall clumps also serve as a screen or backdrop in moist sites.How to Identify
Appearance
Size & Dimensions
Height4' - 10'
Width/Spread2' - 4'
Reaches mature size in approximately 3 years
Bloom Information
Detailed Descriptions
Flower Description
mauve-pink to dusky purpleFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 6-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Joe-Pye weeds grow in full sun to part shade on moist to wet soil at pH 5.5 to 7.0 and are hardy across USDA zones 4 to 9. They need consistent moisture and decline on dry, sandy ground, which suits them to rain gardens, pond edges, and low spots. Plants reach full height in two to three seasons and may lean on rich soil or in shade, where stems stretch toward light. Cutting the clump back by half in late spring produces shorter, sturdier plants that flower a little later. Few pests affect the genus, though powdery mildew can appear in dry, crowded sites. Deer tend to pass over the foliage.Pruning
Cut Eutrochium spp. stems to the ground in late winter or early spring before new shoots emerge. Cutting the clump back by one-third to one-half in late spring reduces height and the need for staking, at the cost of a later, shorter bloom. Spent seed heads can be left through winter for structure and birds.Pruning Schedule
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early spring