Knotgrass (Polygonum aviculare)
The branched stems have what look like knots where the leaf joins and are covered in a silvery scale. The leaves have a short stalk. An annual, it flowers from spring to autumn, with the small, white flowers clustering between leaf and stem. From July onwards, seed is produced for four months.
Knotgrass can grow up to around 60cm, but it usually creeps close to the surface. It is often seen on light, sandy soils. It has a strong taproot and knotgrass can regenerate if the top is chopped off.
Unless removing by hand, use Greenor to control at a time when the weed is growing.
Greenor is a selective, systemic, post emergence turf herbicide.