In short: To repair a bare patch in a lawn, loosen the soil, sow grass seed at 25–35 g per square metre and cover it with about 5 mm of damp coco coir — or pre-mix one level tablespoon of seed into each litre of damp coir and spread that. Keep it moist for two to three weeks and make the first cut at 5–7 cm. This is the same method as the branded "seed, feed and coir" patch kits, made from a compressed brick for a fraction of the price: one 5 kg brick covers well over a hundred patches. Repair in early autumn (September to early October) or spring (late March to mid-May).
Why lawns get bare patches
Most patches trace back to one of a few causes, and fixing the cause is what stops the patch coming back:
- Dog urine — concentrated salts and nitrogen scorch the grass in a ring with a dark green edge.
- Wear — paths, goalmouths, the route to the bins.
- Shade and damp — under trees and along north-facing fences; moss moves in as grass thins.
- Scalping — mowing too low on bumps.
- Pests — chafer grubs and leatherjackets eat roots; the turf lifts like a carpet and birds tear at it.
- Spills and heat — barbecue ash, fuel, paddling pools left too long.
When to repair a lawn
Seed needs warm, moist soil. Early autumn — September into the first half of October — is the best window: the soil is warm, rain is reliable and weed competition is falling away. Spring — late March to mid-May — is the second. In summer the patch dries out faster than you can water it; in winter the seed simply sits there. The RHS gives the same two windows for repairs.
What is in a shop-bought lawn repair kit?
Look at the label of the best-known patch products and you will find three things: grass seed, a small amount of feed, and coir. The coir is the clever part — it absorbs several times its own weight in water, wraps the seed in a damp layer so it does not dry out between waterings, and changes colour as it dries so you can see when to water again. Those kits are convenient, but you pay a premium for a kilo or two of mostly coir. A 5 kg compressed brick expands to about 75 litres, and grass seed by the bag costs far less per patch — so you can make your own mix with exactly the seed your lawn needs (shade mix under trees, hard-wearing ryegrass on the path).
The home-made lawn repair mix
| Ingredient | Amount | Notes |
|---|---|---|
| Damp, expanded coco coir | 1 litre | Squeeze a handful: it should hold together without dripping |
| Grass seed | 1 level tablespoon (about 5–7 g) | Match the seed to the spot — shade-tolerant, hard-wearing or general |
| Sharp sand (optional) | Up to ½ litre | Only where the patch has sunk and needs levelling |
| Lawn feed | None in the mix | Feed the whole lawn as normal instead; feed in the mix can scorch seedlings |
One litre of mix spread 5 mm deep covers about 0.2 m², which works out at roughly 25–35 g of seed per square metre — the standard overseeding rate. Scale it up in the same proportions for bigger areas.
How to repair a bare patch, step by step
- Clear it. Rake out dead grass, moss and debris. If a dog caused it, flood the area with a watering can first to dilute the salts.
- Loosen the soil with a hand fork to 2–3 cm and break up any crust. Compacted patches will not root.
- Level if needed. Fill a hollow with a little sharp sand and coir so the repair finishes flush with the lawn — a sunken patch gets scalped by the mower and fails again.
- Apply the mix about 5 mm deep and firm it gently with the back of a rake or your hand. Alternatively, sow the seed directly and cover with 5 mm of plain damp coir.
- Water with a fine rose so nothing washes away.
- Keep it moist for 2–3 weeks. The top centimetre must not dry out — the coir buys you time between waterings, it does not replace them. Ryegrass shows in 7–14 days; fescues take longer.
- First cut when the new grass reaches 5–7 cm, on a high setting. Keep off it as much as you can for a month.
- Feed the whole lawn on your normal schedule once the new grass has been cut twice.
Patches that keep coming back
- Same dog, same spot: water the area after each visit, or train the dog to a gravel corner. Repairs will not outlast the cause.
- Shade: switch to a shade-tolerant seed mix, mow higher there and lift the lowest branches. Some deep shade will never carry grass — consider a woodland-style planting instead.
- Wear: lay stepping stones on the path line and repair the edges.
- Grubs: if the turf lifts easily, pests are the cause; treat first (nematodes in late summer), repair after.
- Waterlogging: aerate with a fork or hollow tiner and brush a sand-and-coir mix into the holes before reseeding.
How much coco coir do you need?
A hand-sized patch (about 30 cm across) takes roughly half a litre of mix, so one 75-litre brick will repair well over a hundred patches — and the unused coir keeps indefinitely if you let it dry out. For a whole-lawn overseed rather than spot repairs, see the coverage table in coco coir for lawns, or use the calculator.
Frequently asked questions
Can I use coco coir instead of topsoil to repair a lawn?
Yes — for covering seed it is better than topsoil because it holds far more water and does not cap. Use a little sharp sand or topsoil as well only where the patch needs levelling or body.
How long does a repaired patch take to grow?
Germination in 7–14 days for ryegrass mixes, up to three weeks for fine fescues; a patch that blends in with the rest of the lawn after two or three cuts, so about six weeks in good conditions.
Do I need to add feed to the repair mix?
No. Feed the lawn as a whole on your normal schedule. Granular feed mixed directly into a seed cover can scorch seedlings.
Can I repair patches in winter?
Seed will not germinate reliably below about 8–10 °C soil temperature. Prepare the patch and wait for spring, or lay a piece of turf instead.
Is coco peat the same as coco coir for this?
Yes — coco peat and coco coir are the same material; the fine pith is what you want for a seed cover.
Why use buffered coir?
Raw coir can carry sodium and potassium that hold back calcium and magnesium, which tender seedlings notice first. Washed, calcium-buffered coir with a stated pH of 5.5–6.5 and low EC avoids that — why buffering matters.
One washed, calcium-buffered 5 kg brick — 75 litres, over a hundred patches, free UK delivery.
Shop the 5 kg brick → Coco coir for lawns — the full guide