Herb Robert

• 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.

Photos: WA State Noxious Weed Control Board

• 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.

• 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.