Mulching

A mulch is a soil covering used to keep weed growth to a minimum, to conserve soil moisture and help insulate plant roots from extremes of cold and hot weather.

Mulching with black plastic for instance is a good idea for marrows and can be used to produce crops of potatoes without having to earth them up.

Most mulches, however, are made from organic material - such as those used to improve the soil structure (compost, well-rotted manure, leafmould etc.). To be totally effective they need to be around 5cm (2in) thick, but mustn't make direct contact with the plants.