Mulching

A mulch layer sits on top of the soil rather than being mixed into it, and works mainly by physically blocking sunlight and airflow at the soil surface. That cuts water lost to evaporation, keeps roots insulated from surface temperature swings, and starves weed seedlings of the light they need to germinate.

Organic mulches (bark, wood chips, straw, compost) also break down gradually and add organic matter to the soil as they do, which is a secondary benefit inorganic mulches like gravel or pea shingle don't provide. Organic mulch needs topping up periodically as it decomposes; inorganic mulch lasts much longer but does nothing for soil structure.

In UAE summer heat, mulch has an outsized effect: a 5-10cm layer can drop soil surface temperature by several degrees and cut evaporation roughly in half compared with bare soil, which is one of the cheaper, higher-impact things a garden can have done before peak heat arrives.