How to Prepare Your Lawn for Summer

Why Spring Preparation Matters

Grass in the UK grows most actively from late March to late May. During this window the plant is building roots, side shoots and food reserves. If the lawn is fed, watered and mown correctly in this period, it will enter summer with a deep root system and dense sward that can shrug off a fortnight of dry weather.

If you miss this window, the lawn goes into summer weak. The first hot spell browns it off, you panic and water it daily, the roots stay shallow, and the lawn depends on you for the rest of the summer. Doing the preparation properly in spring buys you a low maintenance summer.

The Spring Preparation Timeline

March: First Cut and Clear Up

Once the soil has warmed and the grass is visibly growing, give the lawn its first cut. Set the mower high, around 50mm, and only take the top third off. The aim is to tidy the lawn, not scalp it. Pick up leaves, twigs and any debris that has accumulated over winter.

Check for compaction in areas of heavy foot traffic. If water sits on the surface after rain, or the ground feels hard underfoot, plan to aerate in April when the soil is softer.

April: Feed, Scarify and Aerate

April is the most important month for summer preparation. Apply a spring lawn fertiliser when the soil is moist and rain is forecast within 48 hours. Spring feeds are high in nitrogen to encourage leaf growth. Apply evenly at the rate on the packet, typically 30 to 50g per square metre.

Two weeks after feeding, lightly scarify the lawn with a spring tine rake or powered scarifier. The aim is to remove dead grass and thatch, not to tear up the lawn. If you scarify too hard in spring you weaken the grass just as it needs to grow. Save heavy scarifying for autumn.

After scarifying, aerate compacted areas with a garden fork. Push the fork in 10cm deep every 15cm, and rock it back and forth to open the holes. Brush a 70/30 sand and soil mix into the holes to keep them open.

May: Mow, Edge and Watch for Weeds

By May the grass is growing fast. Mow weekly with the mower set to 35 to 40mm. Never remove more than one third of the grass height in a single cut. Lower the mower gradually over a few cuts rather than all at once.

Cut a clean edge along borders and paths with a half moon edging iron. A crisp edge makes even an average lawn look well kept. Weed out dandelions and daisies with a long handled weed knife, or spot treat with a selective weedkiller if the infestation is heavy.

Mowing for Summer Resilience

The biggest single mistake UK garden owners make is mowing too short. A lawn cut at 25mm looks neat for a day, but the short grass has no leaf area to photosynthesise, no shade for the soil, and shallow roots. In the first dry spell it goes brown.

Raise the mower to 40mm for family lawns in late spring, and to 50mm in June, July and August. Longer grass shades the soil, keeps the roots cool, and survives drought far better. You will mow slightly less often because the grass grows more slowly when it is not stressed.

Keep the mower blade sharp. A blunt blade tears the grass rather than cutting it, leaving a ragged tip that goes white and is more prone to disease. Sharpen the blade once a year, ideally in late winter before the cutting season starts.

Mowing Heights Quick Reference

Feeding for Summer

A spring feed in early April gives the grass the nutrients it needs to build a dense sward before summer. Use a balanced spring fertiliser with an NPK ratio of around 10:3:5. Apply at the rate on the packet when the soil is moist and rain is forecast.

Avoid feeding after mid May. Late feeds push soft, lush growth that is exactly what you do not want going into a hot dry summer. The grass becomes top heavy, the roots do not keep up, and the lawn is more prone to disease.

If you want a second feed, use a slow release summer fertiliser in mid June at half the spring rate. Slow release feeds drip feed nitrogen over 8 to 12 weeks and produce steady growth rather than a flush.

Watering in Summer

Most established UK lawns do not need watering to survive summer. The grass goes brown and dormant in dry weather, but the crown and roots stay alive. When the rain returns, the lawn greens up within a week or two.

If you decide to water, do it properly. A light daily sprinkle encourages shallow roots and makes the lawn dependent on you. A deep soak once a week, the equivalent of 25mm of rain, encourages roots to grow down to find moisture. Water in the early morning or late evening to reduce evaporation.

To measure how much you are watering, place an empty tuna tin or similar shallow container on the lawn. When it has 25mm of water in it, you have watered enough. This typically takes 30 to 60 minutes with a sprinkler depending on water pressure.

Weed and Moss Control Before Summer

Hand weed dandelions, plantains and daisies with a long handled weed knife in April. Get the whole taproot or they will return. For heavy infestations, use a selective lawn weedkiller in mid May when the weeds are growing actively. Do not use a total weedkiller such as glyphosate on a lawn.

For moss, the best approach in spring is to address the cause rather than kill the moss. Aerate compacted areas, raise the mowing height, and accept some moss in shaded areas. Heavy scarification and iron sulphate treatment are best done in autumn when the grass has time to recover. See our guide to moss in lawns for the full process.

Drought Planning for New Lawns

If you are sowing or turfing a new lawn in spring, choose a grass seed mix suited to your conditions. For family lawns, a ryegrass and fescue mix is hard wearing and reasonably drought tolerant. For shaded lawns, look for a shade tolerant mix with more fescue and bentgrass.

Avoid pure ryegrass mixes for lawns that may experience drought. Ryegrass has shallow roots compared to fescue and browns off faster. See the RHS guidance on choosing lawn seed for more detail.

If you are laying turf, lay it in mid March to mid April so it has time to root before summer. Turf laid in May or June needs daily watering for the first month and is at high risk of failure in a dry spell.

Common Summer Lawn Problems

Brown patches

Brown patches in summer are usually drought, dog urine, or a buried object such as a stone or rubble just below the surface. Check the patch with a fork. If the soil is rock hard, it is compaction or rubble. If the patch is uniformly yellow with a green ring around it, it is dog urine. If the whole lawn is brown, it is drought.

Fairy rings

Fairy rings are dark green circles of grass, sometimes with mushrooms, sometimes with a ring of dead grass inside. They are caused by fungi breaking down organic matter in the soil. They are hard to eliminate. Aerate the ring thoroughly, water it well, and mask the dark green with a nitrogen feed.

Red thread

Red thread appears as small pink or red patches on the leaf blades in humid summer weather. It is a sign of nitrogen deficiency. A light feed with a nitrogen rich fertiliser clears it within two weeks.

Summer Maintenance Calendar

When to Get Professional Help

If your lawn has been failing for several summers in a row despite good maintenance, the problem is almost certainly in the soil. Compaction, poor drainage, a thin layer of topsoil over rubble, or a pH problem will defeat any amount of feeding and watering. A professional can do a soil test, check for thatch and compaction, and give you a renovation plan.

For lawns that need a full renovation, see our lawn recovery service page. Most renovations are best done in early autumn, not spring, so book an assessment in August or September if you think your lawn needs it.

Frequently Asked Questions

Should I water my lawn every day in summer?

No. Daily light watering encourages shallow roots and makes the lawn weaker. Water deeply once a week, applying the equivalent of 25mm of rain, and the roots will grow down to find more moisture. The lawn will be more drought tolerant as a result.

Why does my lawn go brown in summer even when I water it?

Usually because the watering is too light and too frequent. It can also be because the soil is compacted, so the water runs off rather than soaking in. Aerate the lawn in spring and water deeply once a week. If the lawn is on very shallow topsoil over rubble, no amount of watering will keep it green in a hot summer.

Is it worth feeding the lawn in summer?

A light feed with a slow release summer fertiliser in mid June can help, but avoid high nitrogen feeds after mid May as they produce soft growth that is damaged by drought. If you only feed once a year, do it in early April with a spring fertiliser.

When should I stop mowing in summer?

You do not need to stop mowing, but you should mow less often and at a higher setting in hot, dry weather. If the grass has stopped growing, do not mow. Mowing a stressed lawn weakens it further.

Final Thoughts

Preparing a lawn for summer is mostly about getting the basics right in spring. Feed once in early April, mow at 40mm or higher, and water deeply when the grass shows stress. The lawns that survive summer best are the ones with deep roots, and deep roots come from good spring preparation and correct mowing, not from constant watering.

If you would like help with spring lawn preparation, or if your lawn needs a more substantial renovation, get in touch with our team. We work across the Chilterns and can give you a realistic assessment of what your lawn needs.

Further Reading

• Why is my lawn full of moss?
• Garden tidy-up checklist before summer
• How often should a gardener visit?
• Lawn recovery service

Sources and citations

This article draws on the following sources. Specific claims are cited inline where relevant.

1. CGM field records (2025-06. Site observations from gardens across Oxfordshire, Buckinghamshire, Berkshire and Bedfordshire.
2. Royal Horticultural Society (2024). RHS Gardening Advice and Plant Finder. Available at rhs.org.uk.
3. Met Office (2024). Regional climate averages, South East England. Available at metoffice.gov.uk.
4. British Geological Survey (2024). Soil parent material data for the Chilterns and Thames Valley. Available at bgs.ac.uk.