Field woodrush identification and control

Field Woodrush Luzula campestris

A member of the rush family, this plant is a common perennial weed of acid soils.

Appearance

Field woodrush has a grass-like appearance that means it can often go unnoticed in a lawn until the brown flowerheads appear in spring.  Leaves are dark green, 2-6 mm wide and tapered with a fringe of white hairs along their edges.

Star-like shaped and dark brown flowerheads are borne on stalks (approximately 20 cm long) in spring, March-May.

These flowers are often very noticeable if grass growth is slow and mowing is yet to commence or is only infrequent

Growth habit

This weed has a fibrous root system and creeping stolons from which it spreads vegetatively.  Also spreads via seed.

Conditions that favour its development

Thrives where thatch has built up and increased acidity and grass growth is weak, often underneath large trees for example.

Cultural control

Ensure that turf is strong and healthy with appropriate maintenance:

• Ensure the plant receives adequate nutrition with sensible fertiliser inputs for growth and conditions.
• Mow regularly and at the correct height of cut for the grass species and growing conditions.
• Water as required to maintain turf health but do not overwater as this will weaken the sward and provide opportunity for weed ingress.
• Control thatch build up by removing surface debris dropped by trees where possible.
• Aerate and top dress regularly to encourage the natural breakdown of organic matter and supplement with occasional scarification of the turf, when grass growth is strong, to remove unwanted thatch.
• Minimise the use of acidifying fertilisers, especially ammonium sulphate.
• Raise the pH level of the soil using ground chalk or lime (avoid hydrated lime) applied in autumn or early winter.
• Mow regularly to remove flowerheads and seeds and always box off clippings

Chemical control

Field woodrush is resistant to selective herbicides. Products containing the active ingredient mecoprop-p may help to check growth but multiple applications are likely to be needed for effective control.

Always apply when both the grass and weeds are growing strongly (usually April-September).