Field wood-rush in lawns

Easily overlooked due to its small stature, field wood-rush is a common sight in the UK countryside and an important food plant for several species of moth. However, in gardens, its brown flowers and broad leaves can be considered unsightly by gardeners wanting a fine, manicured lawn.

Save to My scrapbook
© Shutterstock
© Shutterstock

Quick facts

  • The botanical name for field wood-rush is Luzula campestris; it is also commonly known as Australian glow worm grass, Good Friday grass and chimney sweeps 
  • A UK native, it is commonly found among short grass in pastures and on downland, grassy banks and verges 
  • Its leaves are eaten by caterpillars of several moths and micro-moths 
  • It is sometimes regarded as a lawn weed, particularly on moist, acid soil where it thrives 
  • If you need to control field wood-rush, non-chemical methods are effective

What does field wood-rush look like?

Field wood-rush is a tufted, grass-like

perennial with broad-bladed dark green leaves that are fringed with long, silky, white hairs. In March and April, it produces rounded clusters of dark brown flowers with conspicuous yellow anthers. These sit atop upright green stems and are most noticeable before lawn mowing begins. The flowers are followed by brown fruits containing three seeds.  

It grows to around 15cm (6in) high and often dies back by mid-summer. Underground, it produces fibrous roots and sometimes short rhizomes; overground it creeps by stolons (horizontal stems).

Did you know?

Field wood-rush has some interesting common names. The appearance of its flowers in March and April gave rise to the name Good Friday grass, and in West Yorkshire they were used as a yearly sign to put cattle out to pasture. The shape and ‘sooty’ colour of its flowers have also given rise to the common names of ‘chimney sweeps’ and ‘sweep’s broom’. 

Is field wood-rush a weed?

Field wood-rush is a UK native perennial found among short grass in pastures and on downland, grassy banks and verges. It is a good plant for wildlife, with its leaves eaten by caterpillars of smoky wainscot, double line, broad-bordered yellow underwing and dotted fan-foot moths, as well as those of several species of micro-moth.

Caterpillars of the smoky wainscot moth feed on field wood-rush leaves 
As field wood-rush thrives in damp, acid soil conditions and tolerates full shade and foot traffic, it makes a useful lawn alternative (alongside other species) in gardens where lawn grasses struggle. However, gardeners wishing to maintain a fine, formal lawn are likely to consider field wood-rush as a weed.

What is a weed?

The term ‘weed’ describes a plant that is growing where it isn’t wanted. Weeds usually thrive in average garden conditions, reproducing and spreading easily. It is up to you to decide what you call a weed and what you choose to retain or remove.

Frequently asked questions about controlling field wood-rush in lawns

Here are our answers to your most common questions about controlling field wood-rush in lawns: 

How invasive is field wood-rush? 

Field wood-rush spreads by seed and stolons (horizontal above-ground stems).  

Its seeds are dispersed by ants (see below) and the wind, so you could find seedlings appearing some distance from the parent plant. However, in lawns, regular mowing tends to remove field wood-rush flowers before they can set seed.

Did you know?

Ants are attracted to a fleshy, fat-rich appendage on the outside of the seed coat called an elaiosome. Ants carry ripe seed into their nests and feed the elaiosome to their larvae before depositing the seed in the rich soil of their waste piles, where it germinates.

The main method of spread in lawns is by creeping stolons, and a single plant can work its way slowly through a lawn if allowed to. This is good news if you are trying to establish a species-rich lawn and support your garden wildlife but may not be so welcome if you want an immaculate, fine lawn.  

Do I need to get rid of field wood-rush? 

No – allowing field wood-rush to grow in a species-rich lawn or wild area, or on a grassy bank, is a great way to boost the biodiversity of your garden and support your garden wildlife. However, if you prefer a perfectly manicured lawn, you’ll probably want to remove it.

Field wood-rush grows well alongside other plants in grassy areas on damp, acid soil 

What is the easiest way to kill field wood-rush? 

If you have field wood-rush growing in your lawn where it is not wanted, there are a few ways to remove it: 

  • Improve lawn vigour – field wood-rush thrives in lawns where poor drainage and thatch build-up have weakened grass growth. Follow a programme of lawn maintenance in spring/summer and autumn to boost vigour. Pay particular attention to scarifying and aerating, but be cautious of using high nitrogen fertilisers as some can lower soil pH and thereby encourage field wood-rush. 
  • Mow regularly in early spring (weather permitting) – this removes flowerheads before they have a chance to set seed.  
  • Rake before mowing – to lift creeping stolons and ensure they get caught by mower blades.  
  • Fork out plants – carefully remove individual plants or small clumps using a hand fork, taking care to lift and remove any rooted stolons. Re-seed to repair any resulting bare patches.
  • Lime to reduce acidity – this will discourage field wood-rush and help to limit its spread. See our page on lime and liming.
Top Tip

Don’t add field wood-rush seedheads, rhizomes or stolons to your home compost bin, as it may not reach high enough temperatures to kill them. Instead, put them in your council green waste recycling bin or take them to your local recycling site.

Should I use a weedkiller? 

No – field wood-rush is resistant to lawn weedkillers and it can be effectively controlled using non-chemical methods.   

Join the RHS

Become an RHS Member today and save 25% on your first year

Join now

Gardeners' calendar

Find out what to do this month with our gardeners' calendar

Advice from the RHS

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.