The Gardener's Log

Lawns · · 5 min read

Autumn Lawn Care in the UK: What to Do and When

Autumn is the most useful season of the year for a lawn. The summer stress has passed, the soil is still warm enough for grass roots to work, and rain does a lot of the watering for you. Do the right jobs now and the lawn will come through winter in better shape and start strongly in spring. Do nothing and you tend to find moss, thatch and bare patches waiting for you in March.

The catch, especially in the north of England, is timing. By late October the window for some jobs is closing. This guide runs through what is worth doing, in a sensible order, and what to leave alone if the weather has beaten you to it.

Step 1: Clear the debris

Before anything else, get fallen leaves off the grass. A thick mat of wet leaves blocks light, holds moisture against the blades and encourages disease and yellowing. A spring-tine lawn rake or a leaf blower works well. Do this little and often during autumn rather than leaving it until every tree is bare. There is more on this in our guide to clearing leaves.

Step 2: Mow, but gradually raise the height

Keep mowing as long as the grass is growing, which in much of the UK can be into November in a mild year. As autumn goes on, raise the cutting height by a notch or two. Slightly longer grass copes better with cold, wet weather and shades out some weeds. Avoid mowing when the lawn is waterlogged or frosty - you will tear the blades and leave ruts. The last cut of the year is usually a tidy-up with the blades set higher than in summer.

Step 3: Scarify to remove thatch and moss

Thatch is the spongy layer of dead grass stems and roots that builds up at the base of the lawn. A little is normal, but a thick layer stops water and air reaching the soil. Moss thrives in the same conditions: damp, shaded, compacted ground with weak grass.

Scarifying means raking that layer out. For a small lawn a hand rake and some elbow grease will do. For a larger one a powered scarifier is far quicker. Set it so the blades just skim the soil surface rather than gouge it. Expect the lawn to look rough afterwards - you will pull out a surprising amount of material, and the lawn can look thinner for a while. That is normal, and it is why scarifying should be done early enough in autumn for the grass to recover. If it is already late October, in a cold or wet part of the country a light rake is safer than heavy scarifying. Heavy scarifying can wait until spring.

Never scarify a lawn that is waterlogged or frozen.

Step 4: Aerate compacted ground

Compaction is common on lawns that are walked on a lot, children's play areas and clay soils. Water sits on the surface, grass thins out and moss moves in. Aerating means making holes so air and water can get down to the roots.

On a small lawn, push a garden fork in about 10 cm (4 in) every 10 to 15 cm across the problem areas and wiggle it slightly. For larger areas, hollow-tine aerators remove small cores and generally do a better job than solid spikes on heavy ground. Do it when the ground is damp but not saturated.

Step 5: Overseed thin patches

If there are bare or thin areas, overseeding in early autumn gives the best results because the soil is warm and the damp weather helps germination. Rake the area to loosen the surface, sow a lawn seed mix suited to your use (hard-wearing for family lawns, finer for ornamental ones) at the rate stated on the packet, then lightly rake or top-dress. Keep the area damp if it turns dry. In late October, germination slows down in cold conditions. If you are sowing this late, accept that patchy germination is possible and be ready to repeat the job in spring.

Step 6: Feed with an autumn lawn feed

Spring and summer feeds are high in nitrogen to push leafy growth. Using one in autumn can create soft growth that is prone to disease going into winter. Look for a product sold as an autumn lawn feed, which has lower nitrogen and more potassium and phosphorus to support roots and general toughness. Follow the rate on the pack, apply on a day when the grass is dry and rain is forecast or you can water it in, and never apply more than recommended - overfeeding burns lawns.

Step 7: Deal with moss and weeds sensibly

Moss killers can blacken moss quickly, but they treat the symptom rather than the cause. If you do not also fix drainage, shade and compaction, it comes straight back. Dead moss still needs raking out. Where possible, tackle the cause: prune back overhanging branches, aerate and improve drainage. For broad-leaved weeds like daisies and plantain, hand removal on a small lawn works fine; selective weedkillers work best when the grass is actively growing, so by late autumn they are less effective. Always read and follow the label.

What to avoid

A simple autumn checklist

  1. Rake or blow leaves off regularly.
  2. Raise the mower height gradually.
  3. Scarify and aerate early autumn, if you can.
  4. Overseed bare patches.
  5. Apply an autumn feed.
  6. Keep off the lawn when it is frosty or sodden.

Lawns are forgiving. If you miss the best window this year, do the lighter jobs now and plan the heavier ones for next September. In the next couple of weeks, you might also be preparing your tools for winter so the mower is serviced and ready for spring.