September has always been the traditional time to carry lawn maintenance, but if the summer has been particularly dry or a hosepipe ban has been imposed, wait until autumn rain stimulates the turf and grass is actively growing before carrying out any work.
If your lawn is spongy then it is likely you have a problem with moss. This tiny plant will quickly spread in damp or shaded areas and will overwhelm grass so it needs tackling to keep in check. Remove from the lawn by spreading granules or soaking the problem area with a liquid mosskiller applied from a watering can and leave until it turns black (usually within two weeks).
The dead moss can be removed by raking vigorously with a spring tined garden rake. Large bare patches of soil that are left behind after the moss has been removed should be re-sown with lawn seed.
Although mosskiller works quickly, it is a short term fix and it pays to tackle the causes of moss. To do this, remove overhanging branches that shade the lawn or allow more light through by raising the canopy of trees. If the lawn suffers from compaction or poor drainage it will need aerating (see below).
Grass clippings, moss, weeds and other debris can form a thick mat above the surface of the soil. Known as thatch, this material prevents the lawn from breathing properly, stops rain from penetrating effectively and encourages lawn diseases to prosper.
To remove from the soil, scratch the surface vigorously with a spring tined rake, working your way across the lawn. Add the material that is removed to your compost heap. After raking (also known as scarifying) grasses will respond by producing more side shoots. Large lawns can be tackled with a powered raking machine, available from machinery hire stores.
10 jobs to do in the garden in September.
Lawns that have been subjected to heavy traffic over the summer could be compacted, which will lead to problems with drainage, resulting in the spread of moss or water lying in puddles on the surface.
Improve by plunging a garden fork into the lawn as far as it will go and repeat at 10cm intervals - for large lawns, hire a wheeled spiking machine. Fill the air channels with a ready mixed sandy top dressing bought from the garden centre, working it into the holes with a broom.
Read our tips for dealing with a soggy garden.
Finish by using an autumn lawn feed. These are high in phosphates and potassium, and will result in healthy root growth that will ensure the grass is in the best possible condition to cope with whatever winter throws at it.
Do not be tempted to use a spring feed instead - this is high in nitrogen and will result in soft, sappy growth that is easily damaged by cold weather.