Thoroughwort Eupatorium capillifolium
Other Common Name(s):
Other plants called Thoroughwort:
Previously known as:
- Eupatorium leptophyllum
- Phonetic Spelling
- yoo-puh-TOR-ee-um kap-ill-ih-FOH-lee-um
- This plant has medium severity poison characteristics.
- See below
- Description
-
Dogfennel, is an herbaceous perennial weed in the Asteraceae (daisy) family with finely dissected leaves that are very aromatic when crushed (an aroma that is unpleasant to some). The plant spreads in the landscape by wind blown seeds and spreading rootstocks, sometimes to the point of becoming invasive, so it is important to prevent plants from flowering. Seedlings emerge from spring through early autumn. Plants are difficult to remove and if not removed completely with hand weeding, plants will re-sprout from broken stems. Dogfennel is managed from seed by many broad-spectrum preemergence herbicides; however, herbicide efficacy rankings for this species are based on limited experimental data.
Dogfennel grows rapidly in moist but well-drained soils in full sun to part shade, although it does best with some afternoon shade in hot summer climates. It tolerates most soil types including dry, sandy soils. Plants have good drought tolerance. North of USDA Zone 6, this plant is best given a thick winter mulch and planted in locations affording some protection from harsh winter conditions.
Dogfennel foliage is feathery and can sway gracefully in the wind in an ornamentally attractive manner. However, Dogfennel is poisonous and has been used as an insecticide and antifungal. Dogfennel is native to fields, clearings, woodland margins and roadsides from Florida to the coast to Massachusetts, but is sometimes confused with non-native fennel..
Diseases, Insects, and Other Plant Problems:
No serious insect or disease problems. However, you should watch for powdery mildew, aphids, slugs and leaf miner.
- See this plant in the following landscape:
- Cultivars / Varieties:
-
- 'Elegant Feather'
Sterile cultivar that does not produce viable seed and lacks the invasive characteristics of species’ plants.
- 'Elegant Feather'
- 'Elegant Feather'
- Tags:
- Cultivars / Varieties:
-
- 'Elegant Feather'
Sterile cultivar that does not produce viable seed and lacks the invasive characteristics of species’ plants.
- 'Elegant Feather'
- 'Elegant Feather'
- Tags:
-
-
Attributes:
- Genus:
- Eupatorium
- Species:
- capillifolium
- Family:
- Asteraceae (daisy)
- Uses (Ethnobotany):
- An insecticide and anti-fungal. The entire plant is applied externally as a remedy for the bites of reptiles and insects.
- Life Cycle:
- Perennial
- Recommended Propagation Strategy:
- Division
- Seed
- Country Or Region Of Origin:
- Eastern Canada, Central and Eastern United States
- Distribution:
- Atlantic and Gulf coastal plain, Eastern mountains and Piedmont, Great Plains, North Central and Northeast. Bermuda, Bahamas.
- Wildlife Value:
- Attracts bees and wasps. Eaten by Florida's scarlet-bodied wasp moth, Cosmosoma myrodora, that feed on the plant while mature to store its toxins and ward off predators.
- Particularly Resistant To (Insects/Diseases/Other Problems):
- Tolerates drought and poor soil, deer and rabbits
- Edibility:
- toxic
- Dimensions:
- Height: 3 ft. 0 in. - 6 ft. 0 in.
- Width: 2 ft. 0 in. - 3 ft. 0 in.
-
-
Whole Plant Traits:
- Plant Type:
- Herbaceous Perennial
- Native Plant
- Weed
- Woody Plant Leaf Characteristics:
- Deciduous
- Habit/Form:
- Arching
- Ascending
- Erect
- Growth Rate:
- Rapid
- Maintenance:
- High
- Medium
- Texture:
- Fine
-
-
Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Clay
- High Organic Matter
- Loam (Silt)
- Sand
- Shallow Rocky
- Soil pH:
- Acid (<6.0)
- Alkaline (>8.0)
- Neutral (6.0-8.0)
- Soil Drainage:
- Good Drainage
- Moist
- Occasionally Dry
- Available Space To Plant:
- 3 feet-6 feet
- NC Region:
- Coastal
- Mountains
- Piedmont
- USDA Plant Hardiness Zone:
- 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b
-
-
Fruit:
- Fruit Color:
- Red/Burgundy
- Fruit Value To Gardener:
- Showy
- Display/Harvest Time:
- Fall
- Winter
- Fruit Type:
- Achene
- Fruit Length:
- < 1 inch
- Fruit Width:
- < 1 inch
- Fruit Description:
- Fruits are smooth achenes. Fruiting stems attractive in winter landscape.
-
-
Flowers:
- Flower Color:
- Green
- White
- Flower Inflorescence:
- Corymb
- Insignificant
- Flower Value To Gardener:
- Long-lasting
- Showy
- Flower Bloom Time:
- Fall
- Summer
- Flower Shape:
- Dome
- Flower Petals:
- 4-5 petals/rays
- Bracts
- Flower Size:
- < 1 inch
- Flower Description:
- Flowers are small, greenish-white and borne in large flower heads at the tops of the stems. Blooms from September through November. The small, 3 to 5 flowered heads are numerous and arranged in large, leafy, pyramid-shaped end clusters (corymbs).
-
-
Leaves:
- Woody Plant Leaf Characteristics:
- Deciduous
- Leaf Color:
- Green
- Leaf Feel:
- Smooth
- Leaf Value To Gardener:
- Fragrant
- Leaf Type:
- Compound (Pinnately , Bipinnately, Palmately)
- Simple
- Leaf Arrangement:
- Alternate
- Opposite
- Hairs Present:
- Yes
- Leaf Length:
- < 1 inch
- Leaf Description:
- Each plant produces several tall, stiff, woody-based, often reddish, upright stems clad with crowded, feathery, finely-dissected leaves which are pinnately divided into thread-like segments. Leaves are unpleasantly aromatic when crushed.
-
-
Stem:
- Stem Color:
- Brown/Copper
- Stem Is Aromatic:
- Yes
- Stem Form:
- Straight
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- Long feathery stalks. Stems are erect, reaching 6 feet in height with a woody base. Unpleasant odor when broken.
-
-
Landscape:
- Landscape Location:
- Meadow
- Naturalized Area
- Woodland
- Landscape Theme:
- Native Garden
- Rain Garden
- Design Feature:
- Accent
- Border
- Attracts:
- Pollinators
- Resistance To Challenges:
- Deer
- Drought
- Dry Soil
- Rabbits
- Problems:
- Weedy
