The width of the modified area for shrubs and trees usually is more important than the depth. Adding organic matter to the soil will help improve the environment for root growth. A soil test will tell you what is needed and how much to add. Mulches Mulches serve several important functions in water conservation. They reduce run-off from heavy rains, cool and stabilize soil temperatures, reduce crusting, minimize evaporation, and aid weed control.
Mulches also can be an attractive feature of the landscape.
Excessively deep mulches can injure or kill a plant because they stimulate root growth in the mulch layer. These roots are more likely to experience winter and drought injury than those growing in soil. Maintenance Proper maintenance will greatly influence the longevity and beauty of your design. For example, excessively long intervals between mowings or mowings that remove more than one-third of the top growth can injure turfgrass. This stresses the plants and increases water use.