UK grass species are cool season grasses. They do not like hot weather and get stressed when we get a heatwave. It may not be very often, but when it does occur take these steps to prevent your grass going brown.
1. Keep the lawn healthy.
A healthy grass is much more resilient to hot temperatures. Grass with healthy leaves and deep roots are in a much better position to keep reserves of water. The best way for a green lawn in hot weather is to keep the lawn maintained all year round. Contact your local lawn care service for advice.
2. Mow the lawn high and frequently.
In hot weather you should raise the blades of your lawn mower right to the top. Keeping a longer leaf on the grass helps to shade the soil to slow moisture loss. It also means the grass contains more moisture and able to resist drying out. Regular mowing will also help to keep a fine mulch of chopped grass blades on the soil surface. This will help to keep moisture in the soil.
3. Aerate the lawn.
A hot, dry lawn can become hydrophobic (the soil actually starts to repel water). Water will run off rather than soak in. Spiking the lawn will help the water get down to the root zone and be much more effective. Regular aeration will always result in a healthier lawn as it keeps compaction at bay.
4. Shade the grass.
You may notice that the grass underneath garden furniture will be green in hot weather. This is because it’s sheltered from the hottest parts of the day. If you have a section of lawn which is prone to drying out and going brown, give it some shade. Move a table over the area or put up a patio umbrella. The grass will thank you for it!
5. Reduce feeding.
Applying nitrogen during hot weather can be a recipe for disaster. Dry grass is very likely to react to a high nitrogen lawn feed. Reverse osmosis sucks more water out of the plant, burning it. Be very careful with you summer feeding programme. Switch to liquid feed rather than granular. Apply more potassium and less nitrogen or leave it alone. Contact your local lawn care technician for a suitable summer feeding programme.
6. Keep the lawn watered in a heatwave
Lawns dry out due to lack of water. Most of the UK are on water meters and some people are conservative with their water usage. You may also be under a hosepipe ban from your local water supplier. If you are able to water your lawn it is much better to water deeply and infrequently. Thoroughly wetting the soil will help the grass to grow strong roots and help to prevent it drying out. Shallow, regular watering can have the opposite effect. Causing the grass to grow shallow roots. Water in early morning to increase effectiveness. This will prevent fungal disease and slow water loss due to transpiration. The RHS has a good section on measuring how much to water your lawn. The amount to water will differ depending on your soil and even water type.
7. Apply a water conserver treatment.
If you are able to water your lawn, applying a water conserver treatment will help the lawn use the water more effectively. It breaks down the hydrophobic effect of dry soil and prevents run off. It is a great treatment to apply as part of your regular lawn care programme.
Finally, don’t worry too much if your lawn does end up going brown in a heatwave. Grass is very hardy and will bounce back into growth as soon as it rains again.
If you have any questions or would like arrange a visit from a lawn care professional, please don’t hesitate to get in touch.
Kris Lord
Further reading:
Hi
We recently had our lawn returfed but after a week its already started to go slightly brown and dry
We are watering with a sprinkler everyday.
Is there any treatment or feed you recommend?
Water. In future though, I would recommend seeding a new lawn rather than turfing, especially in a hot summer!
Should I seed or turf my new lawn?