Grass seed & sowing

For a new lawn, prepare a level, firm seedbed with a fine, crumbly surface so grass seed can make contact with the soil. For a bare patch or an existing lawn, you can prepare a much smaller area and leave healthy grass in place. Work when the soil is neither frozen nor waterlogged. Spring and

Grass seed can begin to germinate in around a week to ten days when conditions are favourable; the RHS gives that guide for a newly sown lawn. Treat it as an indication, not a deadline. Soil temperature, moisture, seed-to-soil contact and the grasses in the mixture all affect how quickly shoots appear. Different grasses in

Keep the soil around newly sown grass seed moist while it germinates. When rain is not enough, use a fine spray or watering-can rose so the water does not wash seed into piles. Check the seedbed regularly: a sunny, windy patch can dry much faster than a sheltered one after rain. How often should you

Overseeding means adding grass seed to an existing lawn. It can help thicken areas where useful grass remains but the lawn has become thin or worn. For a small bare patch, you can work locally; where little good grass remains across the whole area, a more substantial renovation may be appropriate. Choose a period when

In the UK, mid-spring and early autumn are usually the best times to sow grass seed. The soil is often warm enough for germination and easier to keep moist than in the height of summer. Early autumn is the RHS’s preferred option when you have a choice, because young grass has time to establish before

A good grass seed mixture suits the conditions where it will grow and the way you use the lawn. Start with the amount of wear, sunlight and mowing you expect, then compare the species and guidance on the packet. A family lawn used for games has different demands from a fine ornamental lawn. A shaded

The amount of grass seed you need depends on the size of the area and the sowing rate for the mixture you choose. Measure the lawn in square metres, multiply by the rate on the seed packet, then convert grams to kilograms. Area in m² × sowing rate in g/m² ÷ 1,000 = seed needed