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 hard frosts.
Use the season as a starting point, then check the ground, forecast and instructions for your seed. Local conditions can vary considerably, particularly between sheltered and exposed gardens.
Sowing in spring
The RHS suggests mid-spring, around March and April, for a new lawn. Wait until the ground is workable and warming rather than frozen or saturated. A cold spell can slow germination, so don’t expect every lawn to be ready on the same date.
Spring sowing gives grass growing time before winter, but seedlings may face dry weather as summer approaches. Plan how you will water gently when rain is insufficient, and check any local water restrictions before starting.
Sowing in early autumn
Early autumn can bring a useful combination of warm soil and moisture. Allow time for the seedlings to grow before colder weather and hard frosts arrive. The RHS also recommends spring or autumn for repairing worn areas.
Keep an eye on the weather: a warm, dry spell may still call for watering, while very wet ground can make preparation difficult. Exposed and shaded areas can cool sooner than sheltered parts of a garden.
Can you sow in summer or winter?
Summer sowing is harder to manage when the surface dries quickly. If you cannot maintain moisture, or watering restrictions apply, waiting for more suitable conditions can save work and wasted seed.
Cold, frozen or waterlogged ground makes winter preparation and establishment difficult. Check the mixture’s guidance and wait for workable conditions rather than assuming seed will germinate promptly in cold soil.
Before you sow
- Check that the soil is workable, with moisture available but no standing water.
- Look at the forecast and allow time to care for the new grass.
- Choose a mixture for the light and wear the lawn receives. Our grass seed guide explains what to look for.
- Measure the area and follow the packet’s sowing rate. Use our seed quantity guide to calculate how much you need.
- Keep people and pets off the newly sown area while it establishes.
If the seed is slow to appear
Different grasses and conditions can produce different germination times. Check whether the surface has stayed moist and whether the seed is in contact with soil or has been washed away. Consult the packet before adding more seed; cooler conditions may simply mean you need to wait longer.