Wondering how to overseed a lawn? You’ve come to the right place. Overseeding an existing lawn helps repair worn and damaged patches to give you a thicker lawn. Using different grass seeds can also help improve the disease resistance of the lawn and improve its overall health. It should be seen as part of your annual lawn maintenance. Read on as we discuss everything you need to know about overseeding your lawn with care.
When Is the Best Time to Overseed a Lawn?
The best time to overseed a lawn is in early spring or early autumn, when soil temperatures are above 7°C and there’s enough moisture to help new grass establish. Professional groundsmen and greenkeepers agree that these seasons offer the ideal conditions for seed germination and growth.
While these seasons are generally ideal, the best time can vary slightly depending on the type of grass seed and where it’s used.
- Domestic Lawn Seed: For home gardens and ornamental lawns, spring and early autumn are perfect. The mild weather helps new shoots develop strong roots before summer heat or winter frost.
- Sports Seed: Sports turf can be overseeded from late spring through early autumn when the soil is warm. Many groundskeepers choose late summer for quicker establishment before the playing season.
- Equine Paddock Seed: Paddocks and grazing areas benefit most from autumn overseeding, giving grass time to strengthen before heavy spring grazing. Avoid very wet or frosty periods, which can hinder germination.
- Agricultural & Commercial Seed: For large pastures or commercial plots, timing often depends on rotation schedules. Early autumn overseeding ensures a thick sward for the following year’s grazing or silage.
- View All Grass Seed: Not sure which mix is right for you? Explore our full range to find seeds tailored to your soil type and use case.
That doesn’t mean you can’t sow in warmer months, just be prepared to water more often, especially during dry spells. Avoid sowing if frost is likely, as it can reduce germination rates and undo your hard work.
Now that we’ve established the best times to overseed different lawn types, let’s get right into how to overseed a lawn.
Step 1: Prepare the Lawn
- The main thing to remember when overseeding a lawn is to incorporate the seed into the existing seedbed as much as possible. Scarifying the area, or at least removing any thatch or moss, is vital in order for the seed to get in contact with the soil.
- The biggest mistake you can make is just throwing the seed on the area and expecting lots of lovely new grass to grow, as it invariably won't.
- If you don't have access to either root zone (a sterilised mix of sand and soil) or spiking/coring machinery, you can substitute this for some good quality dry(ish) sand to mix with the seed. A 1:5 ratio of seed to sand works well. If you can spike the areas that are barest and in the greatest need of attention, then all the better.
Step 2: Sowing the Seed
- Mark out a small area and apply the right amount of seed to get a visual reference. Coverage may need to vary slightly in patchier spots.
- It's very important to keep the area moist as much as possible, so if there has been no rainfall for a couple of days, water the area using a fine spray (evenings are always best, as this means you will lose the least amount of moisture to direct sunshine).
Step 3: Aftercare and Feeding
- If you're using our Pre-Seed and Pre-Turf Fertiliser, then, unlike with a brand new lawn, this needs to be applied after the grass seed has been sown and when the new grass is up and growing (normally around 2 – 4 weeks after germination). What this will do is boost the root system and help the old and new grass incorporate better, giving you a stronger lawn.
- Any leftover fertiliser can be used a few weeks later to further boost your lawn's health.
Step 4: Germination and Growth
- The grass seed can take anywhere between 7 and 21 days to germinate, depending on soil temperatures and moisture levels. It can be frustrating waiting for this to happen, but as long as you have followed the previous steps, then it will germinate. A1 Lawn only provides the very highest quality certified grass seed that has been fully tested to ensure both purity and high germination levels, and we select our mixes and cultivars very carefully.
- Leave the area undisturbed for as long as possible (whilst keeping it moist). Give the new seed time to grow and establish, as the better chance you give it in its early development, the better results will be achieved in the long term.
Step 5: The First Cut After Seeding
- When the new grass has reached a length of around 2-3 inches, it's time to give it its first cut. The main thing to note is not to cut it too short. Only take the top inch or so off the tips of the grass and leave plenty of growth, as overcutting could seriously damage the new blades and lead to considerable die-back.
- There may also still be some seed that is waiting to germinate. Over the coming weeks, this will lead to the lawn becoming thicker and more lush, so it's worth giving the area a bit of time before you consider going over any remaining bare patches.
Step 6: Weed and Moss Control
- Even if you scarify the area prior to overseeding, there is still a chance you won't get all the weeds and moss out of the lawn.
- Don't panic, as these can be treated with a selective weed killer or granular weed, feed and moss killer at a later date.
Need More Help?
Hopefully, after reading this article, you fully understand how to overseed a lawn. In case you have any other questions or concerns or are looking for additional lawn advice, please browse our handy guides section or get in touch with our friendly team of experts. We are more than happy to provide as much information as you need to achieve your lawn goals. You can contact us by phone on 0800 4118141 or by email at sales@a1lawn.co.uk.
