Tree Root Basics

The root system of a tree performs many vital functions. Roots store food needed to produce spring foliage, absorb and transport water and minerals from the soil, and anchor the tree to the ground.

Trees growing in urban areas seldom develop taproots. Root systems actually consist of larger perennial roots and smaller, short-lived, feeder roots. Large, woody tree roots and their primary branches increase in size and grow horizontally. They are usually located in the top 6 to 24 inches of soil.

The small feeder roots constitute the major portion of the root system's surface area. Feeder roots grow out from large woody roots and usually grow up toward the soil surface. At the surface, feeder roots mix with lawn and shrub roots and compete for the water, oxygen and minerals that are more abundant near the surface.

The major function of feeder roots is the absorption of water and minerals. Feeder roots are located throughout the entire area under the canopy of a tree. As much as 50 percent of the root system grows beyond the drip line and may extend as far as the height of the tree.