Field woodrush (Luzula campestris) is a grass-like, perennial weed which spreads using short, creeping stolons. Its broad-bladed, dark green leaves, are fringed with long, silky hairs and it is particularly noticeable when it produces dark brown flower and seed heads, in March or April, before mowing has begun.

It is common in acid conditions, especially where thatch (accumulated dead, fibrous material) has built up and increased acidity. Under such conditions grass growth is too weak to prevent this troublesome weed from establishing.

Field woodrush even grows in chalk and limestone areas where the upper layer of soil has become acidic, due to rainfall and acid-reaction fertilisers such as sulphate of ammonia.

Field woodrush is resistant to lawn weedkillers, but those containing mecoprop-P may check growth if repeated applications are made. However, to eradicate the weed, liming is necessary. Apply ground chalk or ground limestone in late autumn or early winter, after mowing has ended, at 60g per sq m (2oz per sq yd). Do not use hydrated lime. If noticed in spring, try an early application of nitro-chalk, also at 60g per sq m.