Fresh grass clippings are one of the most overlooked free resources in the garden. Applied correctly, they retain moisture, suppress weeds, regulate soil temperature and break down to feed the soil — all at no cost.
How to do it
Dry first (recommended)
Spread fresh clippings in a sunny spot for a few hours until they turn light brown. This prevents them from matting into a hot, slimy layer that blocks air and water from reaching the soil.
Apply in thin layers
Apply 1–2.5cm (½–1 inch) of dried clippings at a time. Fresh clippings should be applied even more sparingly — no more than 1cm at a time. Thin layers allow air flow and prevent anaerobic heating.
Keep away from stems
Leave a 5cm gap around all plant stems, particularly young or tender plants. Contact with stems traps moisture and encourages rotting and slug damage.
Layer with browns for deep mulch
For a deeper no-dig mulch, alternate thin layers of grass (green — high nitrogen) with shredded newspaper or cardboard (brown — high carbon). This speeds breakdown and improves structure.
Top up as it breaks down
Grass clippings break down quickly — usually within 4–6 weeks. Top up the layer regularly through the growing season to maintain a consistent 2–3cm depth.
Watch out
- ✕Never use clippings from lawns treated with herbicides or weed-and-feed products — residues can persist and kill garden plants.
- ✕Do not use clippings from grass that has gone to seed, or you will introduce weeds directly into your beds.
- ✕If slugs are a concern, keep the layer very thin (under 1cm) to avoid creating a warm, damp hiding place for them.
- ✕Avoid piling thick layers against woody stems — this causes bark rot in shrubs and fruit trees.
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