Although some areas have seen the rain return in short bursts of late, your lawn is probably still looking worse for wear after the prolonged dry spell. During extended periods with no rainfall, turf grasses turn brown and stop growing. On the bright side, this often appears worse than it actually is, and the lawn will usually recover quickly with renewed precipitation. It would take a severe drought to completely kill off the lawn.

During dry weather, we recommend you treat your lawn to special care measures. Deprived of water and particularly when the top 10cm (4") of soil dries out, lawn grasses may stop growing and begin to brown. Most likely to suffer are ornamental lawns of the fine, bent-type grasses, whilst general garden lawns containing fescue grasses may be more resilient.

Usually a well-maintained lawn recovers rapidly with the onset of autumn rainfall, especially if appropriate lawn care is carried out. In extended bouts of drought, or where the lawn is not looked after, lawn grasses may become weakened and their roots deteriorate. If the grass becomes sparse, weeds and moss can easily establish with the onset of regular rainfall making remedial action necessary.

If, as predicted, our summers continue to become hotter and drier, then the issue of caring for lawns in drought will become more pressing as water may be too scarce for lawns to be watered. 

Lawn Care During Drought

Mowing

Raising the height of cut on your lawn mower during dry weather will avoid weakening the grasses. If you let the clippings fall back onto the lawn rather than collecting them, they will act as mulch and slow down the evaporation of water from the surface of the soil. Make sure the clippings are small or they may smother the grass and cause damage. Many models of lawn mower on the market today feature a mulch function designed to do just this. This option is available on various petrol lawn mowers and cordless lawn mowers.

Watering

Provided there are no hosepipe bans in force, newly created lawns should be watered thoroughly and regularly. 

Established lawns that need to be kept green should be watered once the soil becomes dry but before the grass colour starts to change. If the ground is very hard and compacted, aerate it by spiking with a garden fork before watering to help water penetration. A hand lawn aerator will make this task even easier.

To minimise water wastage from evaporation, ideally water the lawn in early morning, evening or even night-time. Watering once every seven to 10 days should be sufficient. It is best to avoid applying too much water, which is wasteful and encourages shallow rooting of the grass and promotes moss and turf diseases. Excessive watering can also make the lawn less drought-tolerant in case of hosepipe restrictions or holidays when watering stops.

Calculating how long to leave the sprinkler on

1. Make sure the water reaches a depth of 10cm (4") after each watering. You can use a trowel to open up a test hole a few hours later to ensure the soil is sufficiently damp. By making a note of the watering time required to achieve this level of dampness, future irrigation can be more accurately applied.

2. The average hosepipe sprinkler delivers up to 900 litres (200 gallons) of water per hour. Assuming that the sprinkler covers an area of 9 sq m (97 sq ft), it delivers approximately 100 litres per square metres (22 gallons per square yard) in one hour. Even in the driest months of June or July, one square metre (yard) only requires 20 litres (4.5 gallons) every seven days. On that basis, 12 minutes' steady sprinkling per 9 sq n (97 sq ft) should be adequate.

3. In reality, sprinklers vary considerably in their area of coverage, so the number of minutes required may not be exactly 12. By spacing jam jars over the lawn to catch the water, total water delivery can be estimated. Allowing the sprinkler to run until 2.5 cm (1") of water has been evenly collected in all the jars approximately equals the correct rate of water.

Lawn Care After Drought

The autumn following a dry summer is the ideal time to carry out renovation and repair. In addition to helping the lawn to recover from recent drought, it will also make it more drought resistant the following year.

Sparsely-grassed areas should be over-seeded using the appropriate mixture. 

It is not advisable to use lawn weed killers on drought-effected turf in the autumn. Instead, delay treatments until the following spring when the grass and weeds are growing vigorously. Use a proprietary weedkiller if required.

For an all round treatment of your lawn, we recommend MO Bacter slow release fertiliser which is a granular organic fertiliser that kills moss, feeds grass and improves the soil all in one.

Preventative measures

Whilst drought is not preventable, there are steps you can take to prevent the damage that drought causes your lawn.

The singularly most important thing to do is to ensure that your lawn is healthy to begin with. A regular regime of spring, summer and autumn lawn maintenance will help lawns resist drought and recover strongly afterwards.

If you are sewing or laying a new lawn, take into consideration that there are now drought-resistant grass mixes available which include micro-clovers. Mixtures based on these may prove to be more drought-tolerant and sustainable.

Just a thought...

Ask yourself whether you really need a closely-mown lawn. Why not allow the grass to grow longer and include meadow flowers and bulbs for a more natural environment that will also encourage wildlife into your garden.

Alternatively, replace the lawn with a gravel garden, drought-tolerant border, groundcover plants, decking or permeable paving, for low maintenance of your outdoor space.