Learn how to control invasive knotweed at a series of free workshops, sponsored by King County. Participants will be eligible to borrow the county’s knotweed stem injectors for use on their own land after completing the workshop. Classes will teach property owners safe and effective control methods to eliminate this troublesome species.

Meadowbrook Farm in North Bend will host a workshop from 6:30 to 8:30 p.m. on Thursday, July 23.

Knotweed is a bright green, bamboo-like plant that is conspicuous this time of year along King County roads and rivers, and in numerous backyards and parks. Attempts to control knotweed often result in frustration because of the plant’s tenacity and its tendency to grow in difficult places to access.

According to Justin Bush, King County Noxious Weed Program riparian project manager, the county has been fighting knotweed along rivers for the past 12 years with help from state and federal grants, partnerships with conservation groups, other public agencies and private landowners.

“Invasive knotweed does not respect property lines and has devastating impacts to King County’s most sensitive and high value areas,” Bush said. “Removing knotweed improves habitat for fish and wildlife, and protects streambanks from erosion and failure.”

Bush said cooperation amongst landowners is a key to controlling knotweed, because the plant spreads easily from one property to another by root and stem fragments and creeping underground roots.

To sign up for a class or for more information, visit kingcounty.gov/weeds or call the noxious weed program at 206-477-WEED (206-477-9333).