Purple Loosestrife

Purple Loosestrife

Lythrum salicaria

Information Sheet (PDF)

Colorado List A - Eradication required in Jefferson County

General

• Family: Lythraceae
• Has been sold as an ornamental but no longer available in Colorado
• Introduced from Europe

Habitat

• Infestations are found in wetlands; displaces native species; Reduces waterfowl habitat
• Perennial forb
• Prefers a moist, organic soil but tolerates a wide range of soils
• Prefers sun but tolerates up to 50 percent shade

Plant

Vegetation

• Mature plants are 6 to 8 feet tall
• Narrow leaves attached closely to the stem

Roots

• Tap root with woody lateral branches

Flower

• 2 to 3 million seeds per year
• Color: rose-purple on spike-shaped inflorescence
• Season: June to September

Seedling

• Germinates in spring

Reproduction

• Cut stems
• Root fragments
• Seed

Control

Biological

• Not allowed; eradication is required

Chemical

• View Information Sheet (PDF)

Cultural

• Hand pulling young plants before seed set
• Prevention - maintain health of site

Mechanical

• Burning - N/A
• Grazing - N/A
• Mowing - Not recommended; will spread seed and plants resprout

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