Marble chips, river gravel and crushed brick are popular inorganic mulches. Weed control is important for water conservation. Weeds will compete with desired plants for water and nutrients. A 2-inch layer of mulch is the best defense against weeds. Other methods of weed control in the home landscape include hand pulling, mechanical cultivation and the selective use of herbicides.
Many plants require more nutrients than can be obtained from the native soil.
Nutrients are added in the form of fertilizers. Most fertilizers include nitrogen, phosphorus and potassium. In the spring, plants put the extra nutrients into increased top growth. New growth is undesirable just before a period of drought stress. In the fall, most plants put extra nutrients into root growth, which increases the plant's ability to locate and take up water.