Weed of the Month

English hawthorn (Crataegus monogyna), also known as single-seed or one-seed hawthorn, naturally occurs in Europe, northern Africa, and western Asia.  The species has been present in the Willamette Valley for over 100 years, and is now commonly found in the area.  It usually occurs in disturbed areas with moist soils, including grasslands, pasturelands, and wetlands.  …[Read More]

Japanese knotweed was introduced into the United States from Japan in the 1820’s as an ornamental.  Japanese knotweed is most common in the eastern United States but is becoming more common in the Pacific Northwest.  It is on the Oregon State Noxious weed “B” list and is being targeted for biological control.  It is hard …[Read More]

Description Evergreen, shade tolerant shrub. Leaves are glossy, oblong, dark green, and thick with smooth edges. Leaves are spirally arranged. Flowers are greenish-yellow with a bitter fragrance, blooming late January to May Egg shaped berries start out green and ripen to black in early summer. Where it grows Grows in the understory of native forests, …[Read More]

Weed of the Month Garlic mustard is a noxious weed fairly new to Washington County. The weed is of greatest concern in woodland areas, although it has been identified along road rights-of-way, trails, and streams. Whatever the location, it dominates the area by displacing native vegetation and reducing plant diversity. So how can you identify …[Read More]