Class B Noxious Weed
- Herb Robert is both a winter and a spring annual or bienennial. It is a low growing plant that is hairy and shallowly rooted. Plants have a pungent odor when crushed.
- Flowers have 5 pink petals.
- The leaves are deeply dissected and light green. The foliage turns red in late fall.
- The stems are upright to spreading, hairy and turn red in high light conditions.
The fruit is a capsule. Seeds are brown and about 2 mm in length.
- Found in moist forests with canopy closure and on dry rocky outcrops.
- It is also becoming a significant garden pest in some areas.
- It is found from sea level to mid-mountainous areas in both the Cascades and Olympics.
Reproduction and Spread
- Reproduces by seeds.
- Seeds are ejected in response to drying of the capsule.
- Reports indicate that they may be ejected as far as 15 to 20 feet from the mother plant.
- Easy to hand-pull.
- Herb Robert has a very shallow, weak root system which makes hand pulling easy.
- Aim to pull plants before they go to seed as seeds can survive in the soil for a number of years.
- Frequently monitor sites and control as needed.
- Plants can be mowed or cut back with a string trimmer or weed whacker early in the season before they flower.
Glufosinate, glyphosate, imazapic, imazapyr, metsulfuron, sulfometuron, and triclopyr + 2,4-D gave promising results in initial trials.