Garden guide
Grass Seed Coverage Rates: How Much Seed Per m²?
Sow too little and you get a thin, patchy lawn that weeds happily colonise. Sow too much and the seedlings crowd each other, compete for light and damp off — an expensive way to grow a weak lawn. The right rate depends on the grass: fine fescue seed is tiny and goes a long way, while ryegrass seed is bigger and needs more per square metre. Use the table below, weigh the seed out (a kitchen scale is fine), and resist adding a bit extra for luck.
How to use the rates
Find your mix in the table, then multiply the rate by your lawn area in square metres. A 40m² family lawn sown with a hardwearing mix at 35–50g/m² needs 1.4–2kg of seed — so a 2kg box is the right buy, with a little spare for touch-ups. Overseeding an existing lawn uses roughly half the new-lawn rate, because you're thickening grass that's already there rather than starting from bare soil.
When to sow in the UK
Grass seed needs soil at a steady 8–10°C or warmer, plus reliable moisture. That gives two dependable windows: mid-March to May, and late August to mid-October — autumn is the favourite, because the soil is still warm, rain is more reliable and weed competition is lower. Avoid sowing ahead of frost, or into a summer drought unless you can water daily. In warm, moist soil ryegrass shows in as little as 5 days; fescues can take a fortnight.
Sowing tips that make the difference
Sow onto a firm, fine, level seedbed — rake to a crumb, tread it in, rake again. Split the seed in half and sow in two passes at right angles so you don't get stripes. Rake in lightly (no deeper than 5mm), firm the surface once more, and keep it moist until the grass is established. Net or fleece the area if birds descend. First mow high and gentle at 5–7cm, once the new grass reaches about 8cm.
Always check the bag
These are typical UK rates — blends vary by brand, and coated or quick-germinating seed sometimes carries its own guidance, so the label on your bag wins. And if you'd rather skip the maths entirely, our grass seed calculator works out the weight you need and the cheapest way to buy it for your exact lawn size.
Typical UK sowing rates by grass type
| Grass type | New lawn (g/m²) | Overseeding (g/m²) | 1kg covers (new lawn) | Germination | Best for |
|---|---|---|---|---|---|
| Perennial ryegrass | 40–50 | 20–25 | 20–25 m² | 5–10 days | Family lawns, pets and heavy foot traffic — toughest and quickest |
| Fine fescue (creeping red, chewings) | 25–35 | 15–20 | 29–40 m² | 7–14 days | Ornamental lawns and shaded areas — fine blades, less mowing |
| Tall fescue | 35–45 | 20–25 | 22–29 m² | 7–12 days | Drought-prone and sandy soils — deep roots, stays green in summer |
| Hardwearing mix (ryegrass + fescue) | 35–50 | 20–25 | 20–29 m² | 5–12 days | Most UK gardens — the best balance of looks and toughness |
| Shade-tolerant mix | 30–40 | 15–20 | 25–33 m² | 10–14 days | Under trees and north-facing gardens |
| Wildflower meadow mix | 4–5 | 2–3 | 200–250 m² | 14–28 days | Low-maintenance, wildlife-friendly areas — usually 80% grasses, 20% wildflowers |
Rates are per square metre of prepared soil. 1kg coverage figures are rounded to whole m² — always check your seed bag's own label first.