Rake the lawn first and this will also encourage the grass stems to stand up straight so they are shortened by the mower. This first cut should be on a high setting so that it just trims back some of the stems.
Then look for moss. In a cold, wet winter, moss gets just the right conditions to encourage strong growth, while grass remains dormant and can soon be swamped.
There are several different causes that encourage the return of moss to a lawn – poor drainage, heavy shade, a compacted surface and under-feeding will all have an effect. So try to tackle these first.
Spiking the surface with a garden fork will help to improve drainage and reduce compaction. The resulting holes can be filled with a 50:50 mixture of sharp sand and a lawn soil, which will encourage new roots and better drainage.
Now it’s time to sort out the starvation problem with a dressing of a combined moss killer and lawn fertiliser.
A week or so after applying, the moss will turn dark brown and can be raked off.