Problem: Japanese Knotweed
Problem Info
A very low-growing weed with oval, bluish-green leaves grows in thin and trampled areas of the lawn. Smooth leaves 1 inch long and 1/4 inch wide attach to wiry stems at prominent ''knots'', or joints. This weed forms mats up to 2 feet in diameter. Very tiny greenish-white flowers bloom at the leaf and stem joints from June to November. Prostrate knotweed in a lawn indicates low fertility and compacted soil. It frequently grows in the compacted soils along driveways and in footpaths worn in lawns.
Analysis
Polygonum aviculare Prostrate knotweed, sometimes called wiregrass, is an annual plant that reproduces from its numerous seeds, which germinate in the spring as the soil warms. Prostrate knotweed in a lawn indicates low fertility and compacted soil. It frequently grows in the compacted soils along driveways and in footpaths cut through lawns. Sometimes it is also found in newly established lawns. Knotweed cannot get started in a vigorous, dense turf.
Solution Advice
Divert traffic trampling the grass and loosen compacted soil, or place stepping-stones or paths where people walk. Follow recommended lawn care practices for a healthy, vigorous lawn.
