Lawns: weed control
One gardener’s weedy lawn is another's wildflower meadow. The more plants grow in your lawn, the more biodiverse it will be. If you really want to remove the plants you consider weeds, try hand weeding first and, as a last resort, selective lawn weedkillers are available to use.
Botanical name Various
Areas affected Lawns
Main causes Weeds with creeping stems or seeds
Timing Treat from spring to early summer or dig out in autumn
What are lawn weeds?
Although the term ‘weed’ is subjective, it is usually applied to invasive plants that compete with the grass for space to grow – clover and dandelions, coarse-leaved grasses, daisies and buttercups are just some examples. You may to choose to retain these plants to create a flower-rich lawn. Learn more about making the most of lawns as a wildlife habitat and ways to help our bees;
Bees in your garden
Lawn and mini-meadow habitats
Wildlife in gardens
If you choose to eradicate these plants early identification and prompt removal can alleviate large-scale problems. This can be as simple as following a yearly lawn maintenance plan. The season starts with spring and summer care but autumn care is particularly important.
This page offers options for the gardener if lawn weeds are becoming a problem.
There are several ways lawn weeds are often noticed:
- The grass may look patchy, have an uneven growth rate or simply include areas that are a different colour or texture to the rest of the lawn
- Flowers appear in the grass. This can occur even in a closely mown lawn, but often appears when the grass is allowed to grow longer
- Patches may remain green during a drought. Lawn weeds may perform better or worse than the lawn grasses, staying green or turning brown
Lawn weeds establish because they survive close, regular mowing. They spread by seed or creeping stems, and are usually problematic where the grass is sparse.
First, consider whether you can control the weeds using non-chemical means, such as digging out. Where these methods are not feasible, chemical controls may be needed. Choose a weedkiller that is most appropriate for that purpose by reading the label carefully before buying or using.
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.
There are a number of non-chemical options to try first;
- Feeding, aerating and scarifying will encourage the grass to be more vigorous and so make it more difficult for the weeds to compete
- Remove rosette-type weeds, such as dandelion, daisy and plantain, with a handfork
- Dig out weeds resistant to weedkillers in autumn; and re-turf or re-seed
- Rake over and then mow to discourage creeping weeds such as speedwells, white clover, silverweed and sorrels
- Apply garden lime to acid soils in the winter. Dress with lime at 50g per sq m (1½oz per sq yd) to deter weeds such as sorrels and field woodrush
- Avoid close mowing, particularly with parsley piert and pearlwort, as this can weaken the grass and allow the weeds in
Lawn weedkillers may be needed where many weeds have established. When buying a lawn weedkiller, check the label to find out if it will work on the weeds in your turf.
- Apply a weedkiller in spring and summer, when the grass and weeds are growing vigorously
- Read the instructions before you begin. It is important to follow them and apply the weedkiller as stated – this will ensure effective results and your safety
- Choose a product that is easy to apply. Lawn weedkillers are available to spray on, apply with watering can and dribble bar, and less frequently as granules that are scattered on the surface
- For spot treatment, apply ready-to-use sprays
- Only use with a combined mosskiller where moss is a problem
- Most lawn weeds are killed by weedkiller application, some by a single treatment, but others requiring two or three applications at four to six week intervals
New lawns are often severely damaged by weedkillers if applied to lawns within six months of sowing or turf-laying. However, products containing fluroxypyr (Weedol Lawn Weedkiller) as one of their ingredients are claimed to be safe to use if applied after two months of sowing or laying turf. The new turf must be growing well.
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.
Weedkillers for gardeners (Adobe Acrobat pdf document outlining weedkillers available to gardeners; see sections 1b, c and d)
Composting treated clippings
What can you do with lawn clippings after applying a weedkiller?
- Do not add the first lawn clippings after application to the compost heap
- The next three mowings, especially from products containing clopyralid (which is very persistent), should be used as a mulch only after composting for at least 9 months. If in doubt, check pack for manufacturer's recommendations. The following weedkillers contain clopyralid Vitax LawnClear 2, Weedol Lawn Weedkiller, Vitax LawnClear 2 Green Up Lawn Liquid Feed & Weed (also contains fertiliser)
- 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. Lawnmowers with a 'mulching' function are particularly effective
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.