One person’s weedy lawn is another's wildflower meadow, so decide if you really need to combat these plants. If you do, try working on the principle of preventing weeds growing within the sward, rather than eradicating them when they appear.
Get to know your lawn weeds, their individual growth habits and the conditions they thrive in. Early identification and prompt removal can alleviate large-scale problems in the future. This can be as simple as following a yearly lawn maintenance plan, keeping your lawn in the best possible conditions and minimising stress.
Hand weeding
Use a handfork to remove scattered rosette-type weeds such as dandelion (Taraxacum officinale) and plantain (Plantago species) when the soil is moist, gently re-firming the turf. Lawn weedkillers may be needed where many weeds are established, particularly weeds with a creeping habit such as clover (Trifolium species) and sorrel (Rumex acetosa).
Weedkillers
When buying a lawn weedkiller, check the label to find out if it will work on the weeds in your turf. For example, daisies are resistant to the active ingredient mecoprop-P but are killed by 2,4-D, whereas white clover is controlled by mecoprop-P but is resistant to 2,4-D. For this reason, lawn weedkillers usually contain two or more active ingredients.
Most lawn weeds are killed by weedkiller application, some by a single treatment, others requiring two or three applications at four to six week intervals. A few are very resistant to lawn weedkillers, such as mind-your-own-business (Soleirolia soleirolii), annual meadow grass (Poa annua) and field woodrush (Luzula campestris).
Application
Use lawn weedkillers in spring or early summer when growth is vigorous. Apply in cool, moist, calm conditions when there is least risk of accidentally damaging nearby garden plants. Weedkillers are usually applied as water-diluted sprays using a low-pressure sprayer or watering can and dribble bar. They are also contained in some granular spring/summer lawn fertilisers.
Resistant weeds
Deal with resistant weeds by digging out patches in the autumn, then re-turfing or re-seeding.
Moss
Moss thrives where grass is weak. Use lawn sand or mosskiller in autumn or early spring. Rake out the dead moss, aerate if poorly drained, then apply an autumn or spring fertiliser.
Further information
A conservation and environment leaflet is available from the RHS on the use of garden chemicals. Click here for a summary of RHS policy.