PUBLIC NOTICE: Poison Hemlock identified in Molalla

Poison hemlock plant with flowers in bloom.

The City of Molalla is issuing a warning for residents to be on the lookout for poison hemlock. This noxious weed, which is present in every county in the Oregon, has recently been identified within the city limits.

Poison hemlock is a biennial plant that can grow as tall as four to nine feet. The hollow stem is smooth and hairless and has very distinctive purple blotches all over it. It also has large, glossy green, finely divided, fern-like leaves that are smooth and hairless. Its flower is similar in appearance to Queen Anne’s lace and wild carrot.

Poison hemlock is toxic and can be fatal to humans, pets, and all classes of livestock. All parts of the plant are known to be poisonous, even after the plant has died. Symptoms can include dilation of the pupils, dizziness, and trembling followed by slowing of the heartbeat, paralysis of the central nervous system, muscle paralysis, and death due to respiratory failure. Direct contact with the skin can cause irritation and rashes. If you suspect you or someone else has ingested the plant, call 911 immediately.

Poison hemlock is very easy to control and eradicate with hand pulling and the use of herbicide treatments. If found, the City advises to remove the weeds by pulling, wearing rubber gloves and protective clothing and following up with an herbicide to prevent future growth. Once the plant and its roots are extracted from the ground, place the plant into a plastic garbage bag and dispose of it into a trash receptacle. Avoid mowing and burning and do not attempt to compost poison hemlock as the poisons are persistent. When using an herbicide to control and eradicate poison hemlock use an approved herbicide and always follow the label and safety instructions on that label.

For additional information on Poison Hemlock and its removal, feel free to contact the Clackamas County Soil and Water Conservation District WeedWise Program at 503-210-6000.