Description

Prostrate knotweed is a summer annual, which forms dense patches. Prostrate knotweed is probably the earliest of the summer annuals to germinate in the spring. Prostrate knotweed is often confused with first-leaf crabgrass. Prostrate knotweed is a prostrate weed that produces a thin taproot and multiple branched stems. Even though knotweed does not root down at the nodes of the stems, a single plant can form a dense mass up to three feet across. Prostrate knotweed tolerates extremely compacted soils and is often found in high traffic areas. The leaves appear alternately on the stems, and differ in the color of green depending on the age of the leaf, with older leaves being a less intense green. The stems will be knotty and have a paper like sheath. The flowers of knotweed are small pink to white and form in clusters in the leaf axis. Flowers form in late spring. Knotweed spreads by seed. Prostrate knotweed is found throughout North America.