Tall Thoroughwort Eupatorium altissimum
Other Common Name(s):
Previously known as:
- Eupatorium saltuense
- Phonetic Spelling
- yoo-puh-TOR-ee-um al-TIS-ih-mus
- Description
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Tall boneset is a herbaceous perennial in the daisy family (Asteraceae) native to much of the eastern and central United States and Canada. It can be found growing in fields, prairies and open woods over limestone soils. Genus name comes from the Greek name for these herbaceous and shrubby plants in honor of Mithridates VI Eupator, 132-63 B.C., King of Pontus. Specific epithet means especially tall or towering, referring to the height of the plant.
Tall boneset grows 2 to 6 feet tall and 2 to 3 feet wide on a single stem that branches near the top. Grow in full sun to partial shade in dry to moist, well-drained garden soil. The plant readily reseeds itself, so deadhead spent blooms if this is not desirable. They can also spread by rhizomes.
Flat-topped clusters 4 to 8 inches across with many whitish star-shaped disc flowers appear late summer into fall. Flowers attract many pollinators. The achenes that follow have seeds with tuft of dull white to light brown hair that are carried by the wind. Native bees nest in the dead, hollow stems, so gardeners are encouraged to cut back dead stems to 12 to 24 inches and allow them to remain standing until they disintegrate on their own. Read more about best practices for stem-nesting bees in this NC Extension publication.
Use tall boneset in naturalized areas, in a pollinator, native or drought-tolerant garden.
Insects, Diseases, and Other Plant Problems: No significant problems. Watch for powdery mildew and aphids.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Eupatorium
- Species:
- altissimum
- Family:
- Asteraceae
- Uses (Ethnobotany):
- Has been used medically.
- Life Cycle:
- Perennial
- Recommended Propagation Strategy:
- Division
- Seed
- Country Or Region Of Origin:
- Central and eastern North America
- Distribution:
- AL , AR , CT , DC , FL , GA , IA , IL , IN , KS , KY , LA , MA , MD , MI , MN , MO , MS , NC , NE , NJ , NY , OH , OK , PA , SC , TN , TX , VA , WI , WV Canada: ON
- Wildlife Value:
- It attracts various pollinators and is a larval host plant for Schinia trifascia (three-lined flower moth). Dead stems are used by stem-nesting bees.
- Dimensions:
- Height: 2 ft. 0 in. - 6 ft. 0 in.
- Width: 2 ft. 0 in. - 3 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Herbaceous Perennial
- Habit/Form:
- Erect
- Growth Rate:
- Medium
- Maintenance:
- Low
- Texture:
- Medium
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Cultural Conditions:
- Soil Texture:
- Clay
- Loam (Silt)
- Sand
- Soil pH:
- Neutral (6.0-8.0)
- Soil Drainage:
- Good Drainage
- Moist
- Occasionally Dry
- Available Space To Plant:
- 12 inches-3 feet
- NC Region:
- Coastal
- Mountains
- Piedmont
- USDA Plant Hardiness Zone:
- 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
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Fruit:
- Display/Harvest Time:
- Fall
- Winter
- Fruit Type:
- Achene
- Fruit Length:
- < 1 inch
- Fruit Width:
- < 1 inch
- Fruit Description:
- The achene has seeds with tufts of white to tan hairs that are wind-borne.
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Flowers:
- Flower Color:
- Cream/Tan
- White
- Flower Inflorescence:
- Cyme
- Flower Value To Gardener:
- Showy
- Flower Bloom Time:
- Fall
- Flower Shape:
- Star
- Flower Size:
- < 1 inch
- Flower Description:
- Flat-topped cymes have many star-shaped disc flowers that are whitish to cream colored. They have 5 petal-like lobes with a brown column of white-tipped stamens in the center.
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Leaves:
- Leaf Color:
- Green
- Leaf Feel:
- Smooth
- Leaf Type:
- Simple
- Leaf Arrangement:
- Opposite
- Leaf Shape:
- Elliptical
- Lanceolate
- Leaf Margin:
- Serrate
- Hairs Present:
- Yes
- Leaf Length:
- 3-6 inches
- Leaf Width:
- 1-3 inches
- Leaf Description:
- Leaves are 2 to 6 inches long and 1 inch wide, with minute hairs on the undersides. Leaves have 3 conspicuous parallel veins and there are often smaller leaves in the axils. The base is pointed and there are widely spaced teeth on the upper third of the leaf. They are sessile (stalkless) or nearly so.
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Stem:
- Stem Color:
- Green
- Stem Is Aromatic:
- No
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- Green stems with white hairs. Stems are unbranched except near the top.
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Landscape:
- Landscape Location:
- Meadow
- Slope/Bank
- Woodland
- Landscape Theme:
- Cottage Garden
- Drought Tolerant Garden
- Native Garden
- Pollinator Garden
- Design Feature:
- Border
- Small groups
- Attracts:
- Bees
- Pollinators
- Resistance To Challenges:
- Deer
- Drought
- Problems:
- Weedy
