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Dogfennel

Eupatorium capillifolium (yoo-puh-TOR-ee-um kap-ill-ih-FOH-lee-um)

Family: Asteraceae (daisy) Native Herbaceous (3-15 ft)

Dogfennel is an herbaceous perennial in the daisy family (Asteraceae) with finely dissected leaves that are very aromatic when crushed (an aroma that is unpleasant to some). Widely regarded as a weed in the Southeastern US, dogfennel is grown in perennial borders in the UK, and both the species and the cultivar ‘Elegant Feather’ have earned the Royal Horticultural Society’s Award of Garden Merit. The species epithet is Latin for “hair-like leaves.” 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. If you regard this plant as a weed, know that it spreads in the landscape by wind-blown seeds and spreading rhizomes, so it is important to prevent the 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 resprout from broken stems. Dogfennel is managed by many broad-spectrum preemergence herbicides; however, herbicide efficacy rankings for this species are based on limited experimental data. If you embrace dogfennel as an ornamental, grow it in perennial borders in native, cottage, butterfly, rock or rain gardens Diseases, Insects, and Other Plant Problems: No serious insect or disease problems. However, you should watch for powdery mildew, aphids, slugs and leaf miner.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 73 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (3-15 ft) Optimal soil pH Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Often confused with Foeniculum vulgare

Full plant profile

Growing Conditions
Plant type
Herbaceous Perennial; Native Plant; Weed
Life cycle
Perennial
USDA zones
3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b
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
3 feet-6 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 3 ft. 0 in. - 6 ft. 0 in. | Width: 2 ft. 0 in. - 3 ft. 0 in.
Growth rate
Rapid
Maintenance
High; Medium
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Arching; Ascending; Erect
Texture
Fine
Foliage
Deciduous
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately); Simple
Leaf arrangement
Alternate; Opposite
Leaf feel
Smooth
Leaf value
Fragrant
Leaf size
< 1 inch long
Hairs present
Yes
Leaf detail
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 aromatic when crushed.
Flower color
Green; White
Flower value
Long-lasting
Flower form
Corymb; Insignificant
Flower shape
Dome
Flower size
< 1 inch
Flower detail
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).
Bloom time
Fall; Summer
Fruit color
Red/Burgundy
Fruit type
Achene
Fruit value
Showy
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Fruits are smooth achenes. Fruiting stems attractive in winter landscape.
Stem color
Brown/Copper
Stem detail
Long feathery stalks. Stems are erect, reaching 6 feet in height with a woody base. Unpleasant odor when broken.
Wildlife & Ecology
Native status
Native
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. Adult males of Florida's scarlet-bodied wasp moth, Cosmosoma myrodora, feed on the plant to obtain toxins to ward off predators. Host plant of the larvae of the moths Dichomeris aglaia and Estigmene acrea.
Attracts
Pollinators
Food & Medicine
Harvest time
Fall; Winter
Fruit type
Achene

Edibility

toxic

Uses (ethnobotany)

An insecticide and anti-fungal. The entire plant is applied externally as a remedy for the bites of reptiles and insects.

Landscape Use
Landscape location
Meadow; Naturalized Area; Woodland
Landscape theme
Cottage Garden; Native Garden; Rain Garden; Rock Garden
Design feature
Accent; Border
Garden tags
#fragrant leaves #wind tolerant #native weed #perennial weed #drought tolerant #herbaceous perennial #wind dispersed seeds #poisonous #NC native #aggressive #rabbit resistant #deer resistant #weedy #moth caterpillar host #moth friendly #larval host plant
Problems & Resistance
Other problems
Dogfennel
Problems
Weedy
Resistant to
Deer; Drought; Dry Soil; Rabbits
Particularly resistant to
Tolerates drought and poor soil, deer and rabbits
Propagation
Division; Seed
Poison severity
Medium
Poison parts
Bark; Fruits; Leaves; Roots; Stems
Poison symptoms
Contains liver-damaging alkaloids. Do not consume the plant.
Toxic principle
pyrrolizidine alkaloids
Contact dermatitis
No
Toxicity summary
Medium severity poison; parts: Bark; Fruits; Leaves; Roots; Stems

Planted at Hunnicutt

Nobody’s planted this one yet.