How to overseed an existing lawn

Overseeding is one of the simplest and most effective ways to bring tired, thinning grass back to life. By sowing new lawn seed directly into your existing lawn, you can fill bare patches, improve colour and texture, and help your grass stay thick and healthy all year round. Professional groundskeepers use this method every season and with the right tools and timing, you can too.

Overseeding is best done in early spring to prepare for summer growth or in autumn, when cooler temperatures and rainfall help seeds establish before winter. Both seasons provide ideal conditions for germination and root development.

Did you know... Up to a quarter of an average lawn can die off each year. Regular overseeding helps maintain density, outcompete weeds, and improve resilience against wear, drought and disease.

What Equipment You'll Need

  • Lawn mower

  • Rake or optional powered scarifier

  • Grass seed 

  • Garden fork or hollow-tine aerator

  • Top dressing – sand, compost or loam, depending on your soil type

  • Lawn feed – a balanced fertiliser suitable for the season

  • Watering can, hose or sprinkler

Step 1: Mow Your Lawn Short

Choose a dry day and cut your grass closely. Remove any clippings, debris or moss so new seed can reach the soil surface.

Step 2: Scarify to Remove Thatch

Rake the lawn using a spring tine rake to remove and break up layers of dead matted grass or thatch. This process can be made easier using a powered scarifying machine, however is not necessary. If scarifying in Autumn, it will additionally benefit the side shoots and runners, of the grass plant, as these are developing during this time of year.

Step 3: Aerate The Soil

Spike the ground with a fork or hollow tine aerator up to 15cm (6in) deep to eliminate compaction

Step 4: Apply a Top Dressing

Use a mixture of sand, compost or loam (proportions dependent upon soil type) in order to get denser grass growth and level out minor hollows. The benefit of doing this will improve your lawn’s soil structure and drainage.

Step 5: Feed Your Lawn

Use an appropriate fertilizer (Spring requires high nitrogen and Autumn is low nitrogen). Fertiliser should be applied the same day as sowing grass seed – making sure to evenly distribute the fertiliser with a spreader or rake.

Step 6: Sow Your Chosen Lawn Seed

Ensure the ground is moist (either from rainfall, hose or sprinkler) before sowing. Sow the seed at 25g per m2 (unless specified different). For even more even distribution we recommend using a spreader and mixing seed with topsoil.

Step 7: Rake & Lightly Firm The Soil

Gently rake the seed in and lightly tread to ensure good soil contact. Firming the seed can also be done using a roller, if available. After this we recommend keeping off newly overseeded areas to allow young shoots to gain strength and fully establish.

Step 8: Regularly Water

If dry, water thoroughly with a fine spray to keep the seedbed moist until germination.

Step 9: First Mow

When new grass reaches 5–8cm (2–3in), cut lightly. Gradually lower the blades over time – to around 25mm (1in) for ryegrass lawns or 13mm (½in) for fine lawns. Never remove more than one-third of the growth in a single mow.

The time of year and the weather conditions will effect how frequently you need to mow afterwards. Please see our Lawn Care Calendar for further guidance.

Seed. Feed. Fix.

Quick Fix is our all-in-one seed & feed mix, combining hardwearing, quick germinating grass seed with high quality lawn feed