Mulching trees and shrubs is a good method to reduce landscape maintenance. Mulch eliminates mowing around trees and shrubs, providing a physical barrier that prevents damage from lawn mowers and weed trimmers. A 2-4 inch layer is adequate to prevent most weed seeds from germinating. The mulched area should include as much of the root zone as possible. Individual plants, such as trees, should have a mulched area to extend at least 3-6 feet out form the base of the plant. It is important to pull the mulch 1-2 inches away from the base to prevent bark decay.  Some think that if mulch is good, then the more the better; however, the mulch layer can become too deep. Excessive amounts of mulch can result in a situation in which roots are growing in the mulch and not in the soil. In some cases, pests become a problem in the excessive amounts by tunneling through the mulch and chewing on the roots and plant bark.