Why it matters
Mulch changes the soil surface. Its value depends on where you put it, what it contains and how it behaves after rain. An attractive surface is not proof that roots underneath have the moisture or air they need. Work on one bed first and inspect the result.
What you’ll need
Tools
- Hand fork
- Rake
- Gloves
- Ruler
Materials
- Suitable clean mulch
- Water if needed
Before you begin
Safety & limits
- Wear gloves when handling coarse material. Keep combustible landscaping materials away from ignition sources and follow local fire guidance.
Work carefully, in order
The method
- 01
Match the material to the job
Decide whether the priority is moisture retention, weed suppression or a permanent path. Choose a material suitable for those plants and the site, with a known clean source. Keep questionable treated clippings, seeding weeds and unknown waste out. Record the material so later problems can be traced to an actual input.
- 02
Prepare the soil surface
Remove established weeds without damaging the crop, and check moisture below the surface. Apply over suitable moist soil rather than concealing a dry or waterlogged problem. Mark small plants and direct-sown rows so they do not disappear during spreading. Repair the reason for persistent pooling before treating mulch as the cure.
- 03
Lay an even useful cover
Spread the material evenly at a depth appropriate to its type and your plants. RHS guidance gives roughly 5–7.5 cm for many biodegradable mulches, not a universal rule for every seedling or material. Keep stems and trunks clear. Avoid heaps against a plant merely to use up the remaining bag.
- 04
Test beneath the layer
After watering or rain, lift a small patch and inspect the soil. Check whether water reached it, whether the mulch shifted, and whether a dense mat formed. Compare several places across the bed. Looking under the cover is more informative than watering again because the visible surface appears dry.
- 05
Maintain by condition
Remove emerging weeds while small and replenish material as it breaks down, without burying the plants. Keep a record of the first application and later additions. At the end of the season, note which areas stayed workable and which needed attention. Use that record to revise material choice and quantity.
Mistakes to avoid
- Piling mulch against trunks
- Covering weeds that are already well established
- Applying the same depth around every plant
If it isn’t working
Water sits on top
Check whether the material has matted and review drainage; do not solve the problem by adding another layer.
Plants are disappearing under the cover
Pull material back and reassess spacing, plant size and the intended mulch depth.
Then & now
Historical context
Covering ground with locally available plant material is an old practice; present-day choices should account for contamination, invasive plants and crop requirements.
The modern equivalent
Purchased mulch makes quantity and source easier to track. A marked ruler and regular inspection remain useful regardless of packaging.
Sources & review
Editorial draft — sources checked; specialist review pending. Written 2026-09-20. Sources support the stated scope; this page has not been professionally certified.
- Royal Horticultural Society — mulches and mulching ↗
Mulch selection, application conditions and keeping stems clear. Checked 2026-09-20.
