Deep root feeding distributes the right type and amount of nutrients (macro-nutrients). Macro-nutrients are nutrients that trees need the most and are frequently deficient in a tree. These nutrients (Nitrogen, Phosphorous, Potassium), are vital to tree health. Fertilization of your trees and shrubs can be vital to maintaining health and vigor. Mature trees, young trees, and shrubs can benefit from deep-root fertilization. Complete plant health care services includes fertilizing trees and shrubs. Including tree fertilization in your plant care program will help you to grow hardy plants that will be healthy and have the increased ability to resist insect and disease pests.