Hairy Willow-Herb

hairy-willowherb-flower-2017
hairy-willowherb-habitat-2017
hairy-willowherb-leaf-2017
hairy willow herb plant

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


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.

 Treatment Timeline


JanFebMarAprMayJuneJulyAugSeptOctNovDec
Control











Removal



Small Patches - bag all plant parts and put in trash

Herbicide











Growth











Vegetative











Flowering











Seed