How to Look After Your Lawn in a Heatwave

A run of hot, dry days and the lawn starts to look sorry for itself: pale, then straw-coloured, then crunchy underfoot. It is the point where a lot of gardeners reach for the sprinkler and the mower and, with the best intentions, make things worse.

The good news is that a healthy lawn is tougher than it looks. Here is how to see it through a heatwave, and why the brown you are worried about is usually nothing to worry about at all.

Brown grass is not dead grass

When grass browns off in a drought, it is not dying. It is going dormant, shutting down top growth to protect the crown and roots. It is the same survival trick that gets British lawns through most summers. Once proper rain returns, a dormant lawn greens up within a week or two on its own.

So the first rule is simple: do not panic about the colour. The worst thing you can do to a stressed lawn is stress it further with a scalping cut or heavy foot traffic. Leave it be, and it will come back.

Raise the cutting height

The single most useful change you can make in hot weather is to cut higher. Longer grass shades its own roots and the soil, which slows evaporation and keeps moisture where it is needed.

Raise your mower's cutting height by a notch or two for the summer, aiming for around 40mm rather than a close 20mm to 25mm. Never remove more than a third of the leaf in one cut. If the lawn has already browned and stopped growing, stop mowing altogether until it recovers.

Mulch, do not collect

In a dry spell, stop bagging your clippings and mulch them back into the lawn instead. A mulching mower chops the clippings fine and drops them into the sward, where they act like a thin mulch: shading the soil, slowing evaporation, and returning moisture and nutrients as they break down.

Many modern mowers do this well. The Spectrum TG48-PRO uses a four-blade cutting system that mulches finely, and the Stiga Multiclip 547 S is a dedicated mulching mower with no grass box at all, built specifically for this job. Either keeps clippings on the lawn where, in a heatwave, they do more good than in the bin.

Water well, or not at all

Light daily sprinkling is the classic mistake. It wets the surface, encourages shallow roots, and evaporates before it does much good. If you are going to water, water properly.

• Water deeply and less often. A good soak once or twice a week drives roots downwards. A daily splash keeps them at the surface where they dry out fastest.
• Water early or late. Early morning is best, early evening second best. Watering in the midday sun wastes most of it to evaporation.
• Aerate first if the ground is baked hard. On compacted, sun-hardened soil, water runs off rather than soaking in. Spiking the lawn with a garden fork or an aerator first lets the water reach the roots.
• Or simply let it go dormant. An established lawn does not need watering to survive a British summer. Saving the water and letting it brown off is a perfectly good choice, and often the sensible one during a hosepipe ban.

A few more hot-weather habits

• Keep off it. Dormant, dry grass is brittle and slow to recover from wear. Go easy on the football and the paddling-pool traffic until it greens up.
• Clear the weeds. Weeds compete for what little moisture there is, so pulling them leaves more for the grass you want.
• Hold off on feed and seed. Do not fertilise or oversow in the middle of a heatwave. Feeding pushes tender new growth that cannot cope with the heat. Save it for cooler, damper autumn weather.

FAQs

Should I water my lawn every day in hot weather?

No. Daily watering encourages shallow roots and mostly evaporates. Water deeply once or twice a week instead, early in the morning, or let an established lawn go dormant and recover when the rain returns.

Is my brown lawn dead?

Almost certainly not. Brown grass in a drought is dormant, not dead. It shuts down top growth to protect its roots and greens up again within a week or two of decent rain.

How high should I cut my grass in summer?

Higher than usual, around 40mm. Longer grass shades the soil and its own roots, slowing moisture loss. Never cut more than a third of the leaf at once, and stop mowing entirely if the lawn has browned and stopped growing.

Should I collect or mulch clippings in a heatwave?

Mulch them. Finely chopped clippings left on the lawn shade the soil and slow evaporation, helping the lawn hold moisture. Bagging them removes that free protection when the lawn needs it most.

Kit for a healthy summer lawn

A mower that mulches and adjusts height easily is your best tool in a dry spell. The Spectrum TG48-PRO mulches finely and carries a 5-year warranty, while the Stiga Multiclip 547 S is a dedicated mulching machine. For fuss-free summer cuts, browse the cordless mower range, all with tool-free height adjustment.