Tall Thoroughwort
Eupatorium altissimum
Last reviewed: August 2026
Tall Thoroughwort is a native perennial forb found across eastern and central United States, producing clusters of small white flowers from July through September that attract bees, butterflies, and other pollinators.
Toxicity unknown
Tall Thoroughwort (Eupatorium altissimum) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
medium
Size
36"–72" H × 12"–24" W
Bloom
Jul, Aug, Sep
Native to
AL, AR, CT, FL and 26 more states
Pollinators
bees, butterflies, wasps, beetles
Before you buy
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Tall thoroughwort is a native perennial that forms upright clumps with clusters of small white flowers from summer through early fall. This sturdy plant grows 3-6 feet tall with a narrow spread, making it useful as a vertical accent in gardens.
Growing Tall Thoroughwort
Grow Tall Thoroughwort in full sun and medium water. Mature plants reach 36 to 72 inches tall and spread 12 to 24 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Tall Thoroughwort takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Height can appear overgrown in formal settings
- May look weedy when not in bloom
- Common name includes 'wort' which sounds undesirable
Wildlife value
The late-season blooms provide important nectar for bees, butterflies, and other pollinators when many other flowers have finished. Seeds also feed birds in fall and winter.
Common questions
- When does Tall Thoroughwort bloom?
- Tall Thoroughwort blooms from July through September, producing dense clusters of small white flowers.
- What pollinators visit Tall Thoroughwort?
- This native plant attracts bees, butterflies, wasps, and beetles with its late summer nectar-rich flowers.
- Where is Tall Thoroughwort native?
- Tall Thoroughwort is native to much of the eastern and central United States, from Connecticut south to Florida and west to Texas, Nebraska, and Minnesota.
- What growing conditions does Tall Thoroughwort prefer?
- This adaptable perennial thrives in full sun to partial sun and tolerates a wide range of moisture conditions from dry to wet soils.
- Is Tall Thoroughwort HOA-friendly?
- Tall Thoroughwort takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.
These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.
Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow Tall Thoroughwort? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
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