How to Fix a Patchy Lawn
Last updated: 30 September 2026
Clear the patch, loosen the soil, apply grass seed, cover with topsoil, and keep it moist until germination.
Overview
A patchy lawn is a common problem often caused by poor soil compaction or shade. This guide covers reseeding and restoring bare patches.
Step-by-Step Fix
Before beginning any repair, ensure you have isolated power or water supplies. Clear your workspace, gather standard hand tools, and wear appropriate personal protective equipment (PPE).
- First identify the cause of the patchy lawn. Common causes include shade from trees or buildings soil compaction from foot traffic dog urine or disease. Addressing the root cause prevents the patch from returning after reseeding.
- Prepare the bare patch by removing any dead grass or weeds. Rake the area firmly to loosen the top few centimetres of soil. If the soil is compacted use a garden fork to aerate the area and improve drainage.
- Test the soil pH if possible. Most lawn grasses prefer a pH between six and seven. If the soil is too acidic add garden lime. If too alkaline add sulphur or compost to balance the pH.
- Spread a thin layer of topsoil or compost over the patch and work it into the existing soil. This improves soil structure and provides nutrients for the new grass. Level the surface with a rake.
- Choose the right grass seed for your conditions. If the area is shaded use a shade-tolerant mix. If it is in full sun use a standard lawn mix. If the patch is caused by dog urine use a pet-friendly mix.
- Sow the grass seed evenly over the patch at the rate recommended on the packet. Mix the seed with sand to help spread it evenly. Rake the seed lightly into the soil but do not bury it deeply.
- Cover the seed with a thin layer of topsoil or compost no more than five millimetres deep. Tread the area gently to firm the soil and ensure good contact between the seed and the soil.
- Water the patch thoroughly using a fine spray. Keep the soil moist but not waterlogged. Water daily or twice daily in warm weather until the grass is established which typically takes two to three weeks.
- Once the grass reaches about five centimetres tall cut it lightly with a mower set to its highest setting. Do not cut too short. Gradually reduce the cutting height as the grass matures.
- To prevent future patches maintain your lawn with regular mowing watering and feeding. Aerate the lawn annually. Remove leaves and debris. Treat dog urine spots by watering the area immediately after your dog has been.
Common Symptoms & Diagnostic Resolutions
Review the common error codes and operating symptoms below to quickly identify the root cause of the fault before ordering replacement parts.
| Symptom / Code | Likely Root Cause | Recommended Resolution |
|---|---|---|
| Seed does not germinate | Soil too dry or seed buried too deep | Keep the soil consistently moist. Rake the seed into the surface only not deeply. Water daily until germination. |
| Patch returns after reseeding | Underlying cause not addressed | Identify the root cause. Fix shade issues with a shade-tolerant mix. Aerate compacted soil. Rinse dog urine spots. |
| Moss grows instead of grass | Shade poor drainage or acidic soil | Improve drainage and reduce shade. Apply lawn sand to improve soil condition. Use a shade-tolerant grass mix. |
| Weeds take over patch | Competition from weeds | Remove weeds before seeding. Use a weed killer suitable for new lawns after the grass is established. |
Frequently Asked Questions
How do I fix a patchy lawn?
Clear the patch loosen the soil apply grass seed cover with a thin layer of topsoil and keep the area moist until the grass germinates. Choose the right seed mix for your conditions.
What causes a patchy lawn?
Common causes include shade soil compaction dog urine disease and poor drainage. Identifying the cause prevents the patch from returning.
How long does it take for grass seed to grow?
Grass seed typically germinates in seven to twenty one days depending on the weather and grass type. Keep the soil moist during this period. Do not let it dry out.
Can I fix a patchy lawn in winter?
The best time to reseed is in spring or early autumn when the soil is warm and moist. Avoid reseeding in winter as the seed will not germinate in cold conditions.