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

1. Scarify your lawn to remove moss, weeds and built-up thatch and loosen up the top layer of soil
2. 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
3. Water the fertiliser in until it is fully dissolved (this can take up to 48 hours), once it is dissolved you can overseed
4. Overseed at a rate of 35g per m2, by hand or by using a spreader.
5. Rake the seed in so it is in amongst the soil and firm down by foot to improve seed-to-soil contact
6. 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
7. Remember to clear away any fallen leaves while your lawn establishes
8. 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

1. Dig your soil over to a depth of 20-25cm then rake – this is to help achieve a fine, level and friable seedbed
2. Add topsoil to the area if you believe the soil to be of poor quality, or to level out dips in the lawn
3. 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
4. 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
5. 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
6. Sow your chosen seed at a rate of 50g per m2 by hand or by using a spreader
7. Rake the seed in so that it is amongst the soil and firm down by foot to improve seed-to-soil contact
8. 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
9. Remember to clear away any fallen leaves while your lawn establishes
10. 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
11. Consider applying our SLOW RELEASE: Autumn / Winter feed to protect you lawn from frost and winter-borne disease