Hairy Willow-Herb

Hairy Willow-Herb

Epilobium hirsutum

Information Sheet (PDF)

Colorado List A - Eradication required in Jeffco

General

• Family: Evening Primrose Onagraceae
• Introduced from Europe as an ornamental
• Semi-aquatic herbaceous perennial

Common Names

• Great willowherb, Codlins and cream

Habitat

• Colony forming
• Found in wetlands, drainages, and rights-of-way
• Perennial forb
• Very invasive
• Was sold as an ornamental in the past

Plant

Vegetation

• 1/2 inches wide and up to 4 inches long
• Leaves opposite and lanced-shaped with toothed edges
• Mature plants up to 6 feet tall
• Stem erect and branched with soft hairs

Roots

• Fibrous roots, rhizomes, and stolons

Flower

• ½ - 1 inch wide
• Pink or purple with white center and notched petals
• Season: June to August

Seed

• White silky tuft in long seedpod

Seedling

• Plants re-sprout from roots in the spring

Reproduction

• Seed, rhizomes and stolons

Control

Biological

• None

Chemical

• View Information Sheet (PDF)

Cultural

• Prevention - maintain health of site
• Removal - bag and dispose of plants if seeds have started to develop

Mechanical

• Burning - N/A
• Grazing - N/A
• Mowing - Young plants prior to flower formation

Use all chemicals according to the manufacturer's label. No specific recommendation or endorsement is made or implied by listing methods or products.