Clovers and trefoils are typically trifoliate, having three leaflets, and have white, pink or yellow flowers. In a flower-rich lawn they can be a welcome source of nectar for bees. Bird's foot trefoil (Lotus corniculatus) is a valuable food source for the caterpillars of the Common Blue butterfly.

Learn more about making the most of lawns as a wildlife habitat and ways to help our bees and butterflies:

Bees in your garden

Bees in your garden

Butterflies in your garden

Butterflies in your garden

Lawn and mini-meadow habitats

Lawn and mini-meadow habitats

White or Dutch clover (Trifolium repens) is comparatively large-leaved and has an open habit of growth. The flowers are white or pink. 

Lesser yellow trefoil (Trifolium dubium), a member of the clover family, is a creeping annual weed. It forms a flattened, roughly circular mat of interlaced thin wiry stems, with tiny trifoliate leaves. Many small heads of pale yellow flowers are produced throughout the summer months. 

Other related species include hare's foot (T. arvense) with woolly leaves and flowers, slender trefoil (T. micranthum) bearing tiny yellow flowers, bird's foot trefoil (Lotus corniculatus) with robust stems and bright orange-yellow flowers and black medick (Medicago lupulina) with yellow flowers and clusters of black seeds.

Black medick (Medicago lupulina)

White or Dutch clover (Trifolium repens) may be encountered on all types of soil but is more common on medium to heavy alkaline soils. It forms roots along the creeping, spreading stems.

Lesser yellow trefoil (Trifolium dubium) is usually most troublesome on lighter, sandy soils, particularly where the grass is weak through lack of regular feeding. It forms a deeply penetrating tap root, seeds freely and if scattered plants are ignored, large colonies quickly form. It survives close mowing – a practice which can further weaken turf on poor soils.

Lotus corniculatus (bird's foot trefoil), Medicago lupulina (black medick), Trifolium arvense (hare's foot) and Trifolium micranthum (slender trefoil) spread mostly by seed.

First, consider whether this can be done using non-chemical means such as digging out by hand. Only where this is not feasible, look to using a weedkiller. 

The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.

Cultural control

Try non-chemical control options in the first instance;

• To hand-weed, track back the spreading stems to the origin - any rooted stems should lift off quite easily. Pull and twist the whole plant at once
• Where practical, carefully lift out isolated specimens using a hand fork
• If the weed is widespread, rake the turf to lift stems before mowing and always use a grass-box on the mower to minimise seed dispersal
• Apply lawn fertilisers regularly to strengthen the grass. Begin feeding in April when grass growth starts again with the arrival of settled, milder weather
• Apply a single application of a proprietary spring lawn fertiliser followed at six to eight-week intervals by an application of sulphate of ammonia at 15g per sq m (½oz per sq yd). Its nitrogen content encourages grass growth and acts as a deterrent to the clover
• Even distribution of sulphate of ammonia is essential, or it may scorch or burn the grass. To minimise scorch risk, bulk it out with three or four times its weight of dry sterilised soil or sharp sand. Apply only when the soil is moist and preferably in showery weather
• Alternatively, apply lawn fertiliser at 30g per sq m (1oz per sq yd) in April and repeat the dressing at about six-week intervals
• Do not apply spring or summer fertilisers or sulphate of ammonia after early August. If the grass is still in poor condition in late summer and the lawn has been neglected in the past, apply a proprietary autumn lawn fertiliser in September. If, however, the grass has been regularly fed, don't feed anymore until the following spring. This is because an autumn fertiliser with its higher level of phosphorus, may favour the clover more than the grass!  

Weedkiller control

Lawn weedkillers

White or Dutch clover (Trifolium repens) is relatively susceptible to dicamba, and mecoprop-P (e.g Doff Lawn Weedkiller, Crowne Green Lawn Weedkiller and Westland Resolva Lawn Weedkiller Extra) and may be eliminated after one or two applications. Lesser yellow trefoil (Trifolium dubium), however, shows strong resistance to the majority of lawn herbicides. Products containing fluroxypyr (Weedol Lawn Weedkiller and Weedol Lawn Weedkiller Ready to Use) are particularly effective at controlling clovers, including the more persistent species such as Trifolium dubium. 

The other clover-like species occasionally encountered as lawn weeds, including Lotus corniculatus (bird's foot trefoil), Medicago lupulina (black medick), Trifolium arvense (hare's foot) and Trifolium micranthum (slender trefoil) are similar to Trifolium dubium in their resistance to lawn weedkillers and the same control measures apply. One weedkiller (Weedol Lawn Weedkiller and Weedol Lawn Weedkiller Ready to Use), containing fluroxypyr, MCPA and clopyralid, is also listed as controlling Medicago lupulina.

Applications after August are increasingly less effective and as the majority of clovers found in lawns self-seed freely, further applications the following spring will inevitably be required.

Treated clippings

Do not add the first lawn clippings after application of a lawn weedkiller to the compost heap. To avoid possible contamination of compost, do not collect the clippings at all but mow frequently and allow the short clippings to remain on the surface of the lawn. These will quickly disperse to leave an acceptable finish.

New lawns

Weedkillers often cause severe damage if applied to lawns within six months of sowing or turf-laying. However, materials containing fluroxypyr as one of their ingredients are claimed to be safe to use after only two months.

Inclusion of a weedkiller product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener.

Download

Weedkillers for gardeners (Adobe Acrobat pdf document outlining weedkillers available to gardeners; see section 1b and c)

Links

Chemicals: using a sprayer
Chemicals: using safely and effectively
Chemicals: using spot and broad-scale weedkillers