Drainage, surfaces and lawn
Lawn moss: why it takes over and how to get rid of it
Lawn moss spreads where grass struggles: in shade, on compacted or poorly drained soil, where the lawn is cut too short, or where grass is thin and undernourished. The Royal Horticultural Society advises killing the moss, raking it out (scarifying), then fixing the underlying cause so grass can outcompete it.
- Also known as
- mossy lawn, moss in grass
- Easily confused with
- algae or thatch build-up, general lawn die-back from drought or pests
- How serious
- Low: purely cosmetic, but it returns unless the cause is fixed
- Typical cost
- Usually no cost for DIY control
How to identify lawn moss
Moss shows as soft, springy green cushions among or replacing the grass, usually thickest in shaded areas, under trees, on compacted paths of wear, and in low, damp spots.
It is a symptom as much as a problem: moss colonises where grass is already weak, so its location tells you where shade, compaction, poor drainage or scalping (cutting too short) is letting it in.
How serious is it?
Low: purely cosmetic, but it returns unless the cause is fixed
Lawn moss is purely cosmetic and harmless to people, but a heavily mossy lawn looks poor, feels spongy and crowds out grass.
It tends to return after removal unless the underlying cause is fixed, so the difficulty is persistence rather than seriousness. Removing moss without changing the conditions just resets the clock.
How to fix it yourself
- Apply a moss killer (lawn sand or a proprietary product) following the label, then wait for the moss to blacken and die before raking, as the RHS recommends.
- Scarify (rake out) the dead moss and thatch with a spring-tine rake or a powered scarifier, ideally in autumn or spring.
- Aerate compacted areas by spiking or hollow-tining to improve drainage and air to the roots.
- Tackle the cause: reduce shade where you can, raise the mowing height so you are not scalping, and feed and over-seed thin grass so it outcompetes moss.
- Improve drainage on persistently damp lawns, since constant wet favours moss over grass.
When to call a professional
- The lawn is large, or moss keeps returning despite scarifying and feeding, suggesting a drainage or shade problem that needs more work.
- You want a lawn-treatment programme or significant renovation rather than spot treatment.
Who to call
- A lawn-care or treatment company for scarification, aeration and a feeding programme.
- A landscaper or garden drainage specialist if poor drainage or heavy shade is the root cause.
Frequently asked questions
How do I get rid of moss in my lawn?
The RHS approach is to apply a moss killer, wait for the moss to blacken and die, then rake it out by scarifying. Follow up by aerating compacted soil, raising the mowing height, feeding and over-seeding thin grass, so the lawn can outcompete moss in future.
Why does moss keep coming back in my lawn?
Because moss colonises where grass is weak: shade, compacted or poorly drained soil, scalping from mowing too short, and undernourished grass. If you remove the moss but leave those conditions, it returns. Fixing the cause, not just clearing the moss, is what gives a lasting result.
When is the best time to deal with lawn moss?
Autumn and spring are the usual times to scarify and treat moss, when the grass is growing enough to recover and fill the gaps left behind. Treating moss in the heat of summer or deep winter is less effective because the grass cannot regrow into the cleared areas.
Sources
Editor, HomesAndHedge
Oliver leads HomesAndHedge's editorial coverage of home and garden problems. He researches and writes the plain-English explainers on pests, invasive plants, damp and mould, drainage and wildlife, drawing on guidance from bodies such as the Property Care Association, the RHS and the NHS, and is clear about when a job needs a qualified professional.
Last reviewed: 8 June 2026