How do I get rid of moss in a lawn?
Killing and raking out moss, and fixing the shade, drainage or compaction that let it in.
- Difficulty
- beginner
- Time
- 3 hr
- Read
- 2 min
Short answer
Moss grows where grass struggles — shade, compaction, poor drainage or acidic soil. Kill it, scarify it out and reseed, but unless you fix the underlying condition it will be back within a year.
Moss is a symptom. Removing it without addressing why grass is losing gives you a bare patch that moss recolonises. The removal is a weekend; the underlying fix is what actually solves it.
What you'll need
- Spring-tine rake or scarifier
- Grass seed
- Moss killer or lawn sand (optional)
- Garden fork or aerator (optional)
Step by step
- Identify why the moss is there.Shade, compacted soil, poor drainage, mowing too short, or acidic soil. Usually more than one, and this determines whether the work lasts.
- Apply a moss treatment and wait for it to blacken.Lawn sand or a ferrous sulphate treatment. Usually two to three weeks. Raking live moss spreads the fragments and makes it worse.
- Scarify vigorously to pull the dead moss out.A spring-tine rake or a powered scarifier. The quantity that comes out is genuinely surprising, and thorough is better than gentle.
- Aerate compacted areas.A fork pushed in 10cm every 15cm, or a hollow-tine aerator. Compaction is one of the most common underlying causes.
- Improve drainage where water sits.Top-dress with sharp sand and compost. Persistently waterlogged ground may need proper drainage or a change of planting.
- Overseed the bare areas straight away.Scarifying leaves bare soil, which moss recolonises fast. Seeding immediately gets grass there first.
- Raise the mowing height.Cutting too short weakens grass and lets moss in. Around 4cm suits most lawns, and higher in shade.
- Feed the lawn in spring and autumn.Vigorous grass crowds moss out. A well-fed lawn is the best long-term moss control there is.
Tips
- In deep shade, grass will always struggle. Shade-tolerant seed helps; sometimes the honest answer is planting something else there.
- Ferrous sulphate stains paving and clothing permanently. Sweep it off hard surfaces immediately.
- Autumn is the best time for this whole job — the grass recovers before winter and there is reliable moisture for the new seed.
Common mistakes
- Raking moss out while it is still alive — Moss spreads from fragments. Killing it first and raking the dead material is far more effective.
- Not overseeding after scarifying — You have created bare soil, and moss colonises it faster than grass will arrive on its own.
- Treating the moss and ignoring the cause — Shade, compaction and drainage do not change on their own, so it returns within a year.
Questions people ask
Why does moss keep coming back in my lawn?
Because the conditions favour it over grass — shade, compaction, poor drainage, or mowing too short. Killing the moss without changing those means it returns within a season.
When should I treat lawn moss?
Autumn or early spring, when the grass can recover and there is reliable moisture for overseeding afterwards. Avoid midsummer drought.