Hairy Willow Herb Epilobium hirsutum

Hairywillow herb is a semi-aquatic annual or perennial in the Onagraceae family native to North Africa and Eurasia.  The soft wooly leaves and stems are the reason for the species name hirsutum which means hairy in Latin. This plant reaches a mature height of 6 feet tall.  

While they are more common in cool regions they occasionally occur as a cool-season weed in warmer areas.  Hairywillow herb grows in moist soils and is often found growing in full sun in wetlands, low areas, in ditches, along roadsides, and along stream beds.  Often found growing with the invasive weed purple loosestrife,  it reproduces through rhizomes or by wind dispersed seed.

Seedlings are small and slow to establish, but once established can be challenging to manage. This weed is becoming more prevalent in container nurseries, likely spreading in contaminated nursery crops. Inspect liners to prevent introduction. Prevent plants from going to seed. Willowherbs are not well managed by herbicides currently labeled for use. Herbicide efficacy rankings for this species are based on limited experimental data.  

Insects, Diseases, and Other Plant Problems: This plant is weedy, can spread aggressively, and has been marked as invasive in some regions including northern parts of the USA.  Do not compost, dispose of this plant in the garbage.