March 5, 2020
Poison hemlock can be deadly toxic to both people and animals. This deadly noxious weed is thick around Columbia County and is still young, the leaves are at a basal rosette stage, which is the best time to treat poison hemlock.
Poison hemlock is an invasive species that rapidly colonizes streambanks, vacant lots, roadsides, pastures and meadows, especially where the soil is moist, outcompeting native plants and desirable species. It is a biennial plant, which means that it typically lives for two years. The first year it forms a basal rosette of leaves. The second year, it develops flowering stems and produces about a thousand seeds per plant.
Small patches of poison hemlock can be carefully dug up, making sure to remove the taproot. Do not cut or mow the plants as they will only resprout. Always wear protective clothing and gloves to prevent accidental exposure to the plant's toxins. Dispose of plants in the trash. Toxins remains potent in dried plant material. Never put pulled plants in the compost or leave them where livestock might eat them. There are a number of herbicides available for controlling poison hemlock in larger infestations. Always read and follow the label instructions before applying any herbicide product.
Plant grasses and other desirable vegetation to provide competition and help prevent further weed establishment at the site.
For additional information, contact the Columbia County Noxious Weed Board at:
Information and photo provided taken from the WA State Noxious Weed Control Board. http://www.nwcb.wa.gov