Mulching - Fundamental Technique for Organic Gardeners - Save Water, Combat Weeds, Protect Soil and Plants - All Suitable Materials, Various Techniques for Different Crops. Mulching means protecting the soil. Not only straw and bark mulch are suitable, but also grass clippings, leaves, plastic sheets, stones, and even waste like ash and cardboard. Mulching keeps the soil moist, suppresses weeds, protects against diseases and pests, and promotes beneficial soil organisms. While some vegetable crops are mulched for only a few months, roses and strawberries prefer permanent mulch. All fundamental techniques for different crops are described, as well as all suitable mulching materials.