What Is Overseeding?
Overseeding is the process of sowing new grass seed over an existing lawn to improve its thickness, colour, and resilience. It helps restore bare patches, outcompete weeds, and reinvigorate tired turf without starting from scratch.
Quick Answer: Overseeding is adding new grass seed to an existing lawn to boost density, repair patches, and improve lawn health. It works best when combined with aeration and top dressing.
Why Overseeding Matters
Over time, all lawns thin out due to weather, mowing, wear and tear, and soil degradation. Overseeding:
- Fills in bare spots
- Introduces improved grass varieties
- Strengthens your lawn against disease and drought
- Helps crowd out moss and weeds naturally
It’s one of the simplest yet most effective ways to upgrade your lawn without the cost of re-turfing.
When Is the Best Time to Overseed in the UK?
The two best times for overseeding are:
- Spring (March to May): Warmer days, occasional rain, and active growth
- Autumn (September to October): Warm soil, cooler air, and consistent moisture
Avoid overseeding in summer heat or deep winter cold—germination will suffer.
Step-by-Step: How to Overseed Your Lawn
1. Mow and Clear the Lawn
- Cut the grass shorter than usual (~2.5cm)
- Collect and remove all clippings
2. Scarify to Remove Thatch and Moss
- Use a scarifying rake or machine
- Clear all loosened material before seeding
3. Aerate to Improve Soil Contact
- Use a solid-tine or hollow-tine aerator
- Focus on compacted or patchy areas
4. Spread the Seed
- Use a lawn spreader for even coverage
- Apply 25–35g per m² (check seed label for exact rate)
5. Rake or Brush the Seed In
- Lightly rake to help seed contact the soil
- Avoid burying it too deep
6. Top Dress Lightly (Optional but Recommended)
- Use fine compost or sandy loam
- Apply no more than 1cm deep
7. Water Gently and Regularly
- Mist daily for the first 2 weeks
- Keep soil moist until seedlings are established
Choosing the Right Grass Seed
Not all grass seed is equal. Choose a mix based on your lawn’s specific conditions:
| Condition | Recommended Seed Type |
|---|---|
| Full Sun | Ryegrass, fescue blend |
| Shaded Areas | Shade-tolerant fescues |
| Coastal Gardens | Salt-tolerant rye/fescue mix |
| High Traffic | Dwarf ryegrass or hardwearing mix |
Tip: For Formby lawns, look for salt-tolerant and drought-resistant varieties.
Common Overseeding Mistakes to Avoid
- Using the wrong seed type
- Overseeding onto a weedy or moss-covered lawn
- Forgetting to aerate or scarify beforehand
- Skipping watering or mowing too soon
Frequently Asked Questions (FAQs)
How soon can I mow after overseeding?
Wait until the new grass reaches 5–7cm, then mow gently with sharp blades.
Can I walk on the lawn after overseeding?
Minimise foot traffic for at least 2–3 weeks to allow seed to germinate and establish.
How long until I see results?
Germination typically begins within 7–14 days in ideal conditions, with noticeable improvement in 3–4 weeks.
Conclusion: A Small Step With Big Results
Overseeding is a simple yet powerful lawn care technique that restores thickness, boosts health, and improves appearance. With the right preparation and follow-through, you can see dramatic improvements in just a few weeks.
Need help overseeding your lawn? Book a professional service.
