Prostrate knotweed is one of several terms for an extremely common weed found in most parts of the country. Named for its tendency to grow “prostrate” or flat across the ground, prostrate knotweed favors compacted soils where it quickly forms a tough, wiry mat across your lawn.
Its tendency to recur and the difficulty of removing prostrate knotweed clumps make weed control particularly frustrating for homeowners. Preventing the spread of prostrate knotweed depends on early recognition of the weed and proper chemical treatment from a weed control professional.
Recognizing prostrate knotweed
Prostrate knotweed plants typically feature small, narrow leaves with smooth margins and whitish sheaths surrounding the stems. If they occur, knotweed flowers will be white or pinkish and show up where the leaf and stem connect.
The unique appearance of its green, leafy seedlings means this weed often is mistaken for young grass. Keep an eye out for the creeping growth pattern characteristic of prostrate knotweed. This summer annual weed also tends to pop up early in the spring, though it can grow throughout the warm months.
How to Get Rid of Prostrate Knotweed
Left untreated, knotweed can quickly overrun a yard, producing chemicals that can stunt the growth of surrounding grass.
Do-it-yourself weed control – while tempting – is not advised for prostrate knotweed: Pulling plants can scatter tiny seeds and mowing these weeds also can increase chances of reseeding.
Instead, have a trained weed control professional treat your lawn with a post emergent herbicide to rid your lawn of prostrate knotweed plants you have now and prevent more in the future.