Mulch placement around trees
Quick answer
Mulch belongs across the root zone and clear of the trunk. Piling it against the bark keeps the stem base permanently damp and is the commonest avoidable cause of trunk problems on amenity trees. Mulch conserves water and moderates soil temperature; it is not a feed.
What mulch does for a tree
- Reduces evaporation from the soil surface — the dominant benefit in this climate.
- Moderates soil temperature in the surface root layer.
- Suppresses competing weed and grass growth in the root zone.
- Protects the surface from wind and dust abrasion.
- Adds organic matter slowly as it breaks down.
None of those is a nutrient benefit. Mulching is not fertilising, and organic mulch cannot be relied on to correct a shortage.
Method
- Clear grass and weeds from the area to be mulched.
- Spread across the root zone — the wider the better, out towards the canopy edge.
- Keep a clear gap at the trunk. The bark should be visible and dry at the base.
- Keep the layer even rather than mounded.
- Renew as it breaks down, which happens faster here than in a temperate climate.
In Kuwait's conditions
The case for mulching is strong: summer maxima of 42–46°C in Dry Summer and 45–46°C in Wet Summer, with 51.3°C recorded on 20 August 1998, and routine wind — thunderstorms averaging 65 km/hour and severe dust storms in the Al-Sarayat season. Bare soil in those conditions loses water quickly and erodes.
Two cautions. Heat accelerates decomposition, so mulch is consumed faster and needs renewing. And on a salt-affected site mulch reduces surface evaporation, which changes how salts move — it is not a substitute for drainage.
No mulch depth is stated: we found no sourced figure for one.
Common mistakes
- Packing mulch against the trunk — the single most damaging error here.
- Mounding it deeply rather than spreading it evenly and widely.
- Expecting it to feed the tree.
- Using coarse un-decomposed material and reading the resulting yellowing as a soil shortage.
- Mulching a poorly drained or saline site instead of fixing the drainage.
Warning signs
Damp, discoloured or soft bark at the stem base where mulch has been in contact is a signal to pull the material back and inspect. General yellowing after a heavy dressing of coarse material points to temporary nitrogen tie-up rather than a soil deficiency.
Related glossary terms
Sources
- FAO — Fertilizer and Plant Nutrition Bulletin 16, Chapter 3.
- Kuwait Meteorological Department — Climate.
All accessed 27 August 2026. Last reviewed: 27 August 2026.