Summer is the hardest season for a lawn. Heat, drought, wear from children and pets, and the mower itself all take their toll, and a lawn that looked lush in spring can look thin, brown and tired by August. The good news is that most summer lawn problems are caused by a small number of habits — mowing too short, watering too often and too lightly, and feeding at the wrong time — and changing those habits will improve a lawn more than any product. This guide covers mowing, watering, feeding and drought care for a summer lawn, in general terms that apply across grasses and climates, with the reminder to check your local extension service for advice suited to your grass type and area.
Mow high in summer
The single most useful summer lawn habit is to mow high. Longer grass shades the soil, keeping it cooler and moister, and it grows deeper roots, which can reach water that short grass cannot. As a guide, set the mower to its highest or second-highest setting in summer, and never cut more than a third of the grass height at once — cutting a long lawn short in one pass scalps it, exposes the soil to the sun, and stresses the grass so badly that weeds move in. If the grass has grown long during a wet spell or a holiday, cut it in stages over several mowings, lowering the height gradually.
Mow on a dry day, with sharp blades, because blunt blades tear the grass rather than cutting it, leaving ragged ends that dry out and turn brown. Leave the clippings on the lawn where they will break down and feed the soil, unless they are so long that they smother the grass underneath — in that case, rake them off or compost them. In a hot, dry summer, mow less often, and let the grass grow a little longer between cuts; a lawn that is not growing fast does not need mowing often, and every cut is a small stress on the plant.
Watering a lawn in summer
Water a lawn deeply and rarely, not lightly and often. A thorough soaking once a week, wetting the soil to a good depth, encourages deep roots and a lawn that can cope with heat, while a light sprinkle every day keeps the roots at the surface and leaves the lawn helpless the first time you miss a day. Water in the early morning, so the water soaks in before the heat of the day and the grass dries quickly, reducing disease. If you water in the evening, the grass stays damp overnight, which encourages fungal disease in a humid summer.
A lawn that goes brown in a drought is usually not dead but dormant. Most lawn grasses will green up again when rain returns, even after several weeks of brown, and watering a dormant lawn heavily in a water shortage is often a waste of water. If you do water, water the whole lawn evenly and deeply rather than patching the brown areas, and prioritise a newly sown or newly turfed lawn, which has shallow roots and will die if it dries out. Check your local extension service and your water supplier for any watering restrictions in your area, and follow them. The watering calculator can help you estimate how much water a lawn needs.
Feeding, weeds and pests in summer
Feed a lawn lightly in summer, if at all. A lawn fed heavily with nitrogen in hot weather will grow fast and soft, need more water, and be more prone to disease, while a lawn fed in spring and autumn usually has enough nutrition to get through summer. If the lawn is pale and thin despite adequate water, a light feed with a balanced lawn fertiliser, applied in the cool of the evening and watered in well, can help — but do not feed a drought-stressed lawn, because fertiliser on dry grass can burn it.
Weeds in a summer lawn are usually a symptom, not the problem: a thin, short-mown, dry lawn lets weeds in, while a thick, high-mown, well-watered lawn crowds them out. Pull the worst weeds by hand, mow high, and water deeply, and the lawn will usually thicken and the weeds will fade. Pests such as chafer grubs and leatherjackets can damage a lawn in summer, showing as patches that lift easily or birds pecking at the turf; if you suspect grubs, lift a patch and look, and ask your local extension service for advice before treating, because the treatment depends on the pest and the timing.
Drought, wear and bare patches
In a drought, the best lawn care is often to do less: mow high and infrequently, keep off the lawn as much as you can, and let it go dormant rather than fighting to keep it green. Wear from foot traffic, children and pets is worse on a dry lawn, because the grass cannot recover, so move play areas, garden furniture and washing lines regularly, and avoid walking the same route across the lawn every day. A lawn that is allowed to rest in a drought will recover when rain returns, while a lawn that is worn and watered in a drought may still look thin in autumn.
Bare patches are best repaired in autumn, when the weather is cooler and the seed can establish, but a small patch can be repaired in summer if you can keep it watered. Rake the patch, sow seed or lay a piece of turf, cover it lightly, and water it daily until it has established, keeping feet off it. Do not sow a whole lawn in the heat of summer — the seed will dry out before it germinates, and the young grass will struggle — unless you can water it reliably every day.
A summer lawn checklist
Mow high and never cut more than a third of the height at once, with sharp blades, on a dry day. Water deeply once a week in the early morning, or let the lawn go dormant in a drought. Feed lightly, if at all, and never feed a drought-stressed lawn. Pull weeds by hand, move wear around the lawn, and repair bare patches in autumn, or in summer only if you can keep them watered.
A summer lawn does not need to be perfect to be healthy, and a lawn that is mown high, watered deeply and left to rest in a drought will usually be in better shape in autumn than one that has been fussed over all summer. The habits are simple, and they are the same habits that make every other part of the garden healthier too. For the rest of the summer routine, read our summer watering guide and summer garden cleanup, and browse the guides hub for the full seasonal series.
Frequently asked questions
How short should I cut my lawn in summer?
Mow high — set the mower to its highest or second-highest setting, and never cut more than a third of the grass height at once. Longer grass shades the soil, keeps it moist, and grows deeper roots.
How often should I water my lawn in summer?
Deeply and rarely — a thorough soaking once a week in the early morning is far better than a light sprinkle every day. A lawn that goes brown in drought is usually dormant rather than dead, and it will green up when rain returns.
Should I fertilize my lawn in summer?
Only lightly, if at all. Heavy nitrogen feeding in hot weather makes grass grow soft, need more water and become prone to disease. Do not feed a drought-stressed lawn, because fertiliser on dry grass can burn it.
My lawn has gone brown — is it dead?
Usually not. Most lawn grasses go dormant in drought and green up again when rain returns, even after several weeks of brown. Keep off it, mow high and infrequently, and water only a newly sown or turfed lawn, which will die if it dries out.
When should I repair bare patches?
Autumn is best, when the weather is cooler and seed can establish. A small patch can be repaired in summer if you can water it daily until it establishes, but do not sow a whole lawn in the heat of summer unless you can water it reliably every day.