Knotweed is a bright green plant with a hollow stem similar to that of bamboo. Knotweed can grow upwards to 16 feet tall and spreads by means of roots and fragmentation. Knotweed creates a monoculture and will push out all other plant species, including trees, and eventually impact all life including salmon that need tree shade and roots to create spawning pools. To learn more about this invasive species click here.