Sowing grass seed in September

September may seem like an odd time to be undertaking any gardening work, but it has many benefits that can help give you a head start on your spring / summer 2021 lawn.
September temperatures are still ideal for germination, hitting heights of 8-10 degrees and above. In addition, and in typical UK fashion, there is also usually some rain forecast to keep your soil and new seeds moist – so there is less need to have the hose out, or the sprinkler on stand-by! There is also less chance of weeds and pests invading your new lawn due to slightly milder temperatures, and birds begin to migrate preventing your just-sown seed being gobbled up.
You can overseed and sow a new lawn from scratch in September, but always consult a two-week weather forecast prior to sowing to ensure temperatures are 8-10 degrees and above, with no sudden storms forecast.
Aside from temperatures, to make sure your September sowing is a resounding success, you should make sure to follow all the necessary steps outlined below.
Overseeding your existing lawn in September
- Scarify your lawn to remove moss, weeds and built-up thatch and loosen up the top layer of soil
- Apply our SLOW RELEASE: Autumn / Winter feed at a rate of 35g per m2 by hand when wearing a glove or by using a spreader, this will help to keep your new grass healthy and free from frost damage and disease going into the colder months
- Water the fertiliser in until it is fully dissolved (this can take up to 48 hours), once it is dissolved you can overseed
- Overseed at a rate of 35g per m2, by hand or by using a spreader.
- Rake the seed in so it is in amongst the soil and firm down by foot to improve seed-to-soil contact
- Water the area immediately after sowing, and continue to water it daily for the first six weeks after sowing. Avoid doing this if there is prolonged rainfall
- Remember to clear away any fallen leaves while your lawn establishes
- Mow the lawn when it is established around the 6 week mark on the highest setting on your mower – you can read more on the last grass cut of the season here
Sowing a new lawn from scratch in September
- Dig your soil over to a depth of 20-25cm then rake – this is to help achieve a fine, level and friable seedbed
- Add topsoil to the area if you believe the soil to be of poor quality, or to level out dips in the lawn
- Leave the area to cultivate for a week, removing any weeds that may pop up due to disturbance in the soil. You can do this by hand or by using a weedkiller
- Apply our QUICK RELEASE: Pre-Seed feed at a rate of 70g per m2 by hand when wearing a glove or by using a spreader, this will help accelerate the growth of your new lawn
- Water the fertiliser in until it is fully dissolved (this can take up to 48 hours), once it is dissolved you can sow your seed
- Sow your chosen seed at a rate of 50g per m2 by hand or by using a spreader
- Rake the seed in so that it is amongst the soil and firm down by foot to improve seed-to-soil contact
- Water the area immediately after sowing and continue to water it daily for the first six weeks after sowing. Avoid doing this if there is prolonged rainfall
- Remember to clear away any fallen leaves while your lawn establishes
- Mow the lawn when it is established around the 6 week mark on the highest setting on your mower – you can read more on the last grass cut of the season here
- Consider applying our SLOW RELEASE: Autumn / Winter feed to protect you lawn from frost and winter-borne disease