Russian Knapweed mostly invades open, disturbed ground, such as along trails and roadways. Once established, it spreads aggressively, growing up to 3 feet tall and suppressing growth of surrounding plants. Repetitive annual herbicide applications are recommended for treatment. Although this plant was first introduced in the late 1800’s as a contaminant in alfalfa seed, its spread throughout the watershed may be attributed to “hitchhiking” with increased off-road vehicle use. Noxious weed and invasive plant management involves prevention and early detection, coordination between public and private landowners, inventory and mapping of sites, containment, control and eradication of weeds, restoration of disturbed areas, and lastly, ongoing research to better understand weed ecology and biological control agents. Photo © Joseph M. DiTomaso