False Dill (Eupatorium capillifolium) - How to Grow & Care Guide

Plant Snapshot

Common Name: False Dill
Latin Name: Eupatorium capillifolium
Alternate Names: Dogfennel; hairy boneset
Hardiness Zones: USDA 6–9 (may persist or spread farther in warmer zones; may die back or be shorter lived in colder zones)
Typical Height: 3–6 ft (90–180 cm)
Typical Spread: 2–4 ft (60–120 cm) per clump; larger where it spreads
Bloom Period: Late summer to fall (commonly Aug to Oct in the northern hemisphere)
Soil Preferences: Prefers well drained sandy to loamy soils and tolerates poor and dry soils. Poorly drained heavy soils may reduce vigor.
Light Preferences: Full sun to light shade. Best flowering and denser habit in full sun.
Toxicity: Reported to contain toxic compounds. Ingestion may be harmful to pets, livestock, or people. Wear gloves if handling large amounts and consult poison control for exposures.
Propagation: Seed, division, and stem cuttings. Seed is the primary means of spread in the landscape.

Key Facts

Perennial native to the southeastern United States
Fine feathery, fennel like foliage that is aromatic when crushed
Produces flat clusters of small white flowers in late summer to fall
Can spread aggressively and behave as a weed in warm climates
Tolerates poor, dry soils and often grows in disturbed sites
Prefers full sun but tolerates light shade
Can be propagated by seed and by division or cuttings
Reported to contain compounds that may be toxic if ingested

False Dill (Eupatorium capillifolium) is a perennial native of the southeastern United States with fine feathery, fennel like foliage and flat clusters of small white flowers in late summer to fall. It establishes readily in sunny disturbed sites and can be weedy in warm climates, so place it where spread is acceptable.

Identification

Eupatorium capillifolium has lacy, aromatic foliage that smells when crushed and produces flattened clusters of small white flowers from late summer into fall. Plants commonly reach 3 to 6 feet tall with clumps that spread roughly 2 to 4 feet, though vigor varies by site and climate.

Best uses and where to grow

Use False Dill in meadow mixes, naturalized borders, roadside buffer strips or sunny rough areas where a tall, airy texture is desired. It prefers full sun but tolerates light shade and does well on poor dry soils, which makes it useful on low input sites within USDA zones 6 to 9.

Planting and spacing

Propagate by seed, division or stem cuttings. Space plants about 2 to 4 feet apart to match the typical clump spread and reduce competition. Planting timing varies with local climate, so place transplants where they have room to develop without crowding more formal beds.

Water and soil

False Dill prefers well drained sandy to loamy soils and tolerates poor dry conditions common on disturbed sites. Avoid persistently waterlogged clay which reduces vigor. Once established plants tolerate drought, while regular moisture during establishment helps produce a denser habit and better flowering.

After flowering and maintenance

Deadhead spent flowers to reduce seed fall and limit unwanted spread. Divide congested clumps to rejuvenate growth and to propagate. Wear gloves when handling large amounts because the species is reported to contain compounds that may be toxic if ingested and prolonged contact may be best avoided.

Controlling spread and naturalizing

False Dill can spread aggressively and often behaves as a weed in warm climates, with seed the primary means of spread. To control patches remove seedlings, cut or mow before seeds develop and dig out persistent clumps. Monitor naturalized areas annually to prevent takeover of desirable plantings.

Frequently asked questions

How fast does False Dill grow?: It is often fast growing and can reach its typical 3 to 6 foot height in a single growing season under favorable warm site conditions.
Is False Dill toxic?: Reportedly the species contains potentially toxic compounds. Avoid ingestion and consult a poison control or extension toxicology source for specific risks to people, pets or livestock.
How should I propagate False Dill?: Propagate by seed, division of clumps or softwood stem cuttings. Seed is a common means of spread in the landscape, so handle seed heads with care if you wish to prevent self sowing.
Will False Dill invade other plantings?: Yes it can naturalize and form colonies, especially in warm sunny sites. Use deadheading, removing seedlings and periodic digging to keep it from overtaking smaller cultivated beds.