How Long for Roots to Take on a Transplanted Tree?

Establishment Time

• When a tree is dug up for transplanting elsewhere, it might lost up to 95 percent of its roots. All newly transplanted trees are susceptible to shock until they have developed normal, spreading roots. If you transplant a tree with a trunk 2 to 3 inches in diameter and care for it properly, the tree should be growing vigorously in two to three years. For the tree to fully establish, the roots need to extend beyond the drip line of its canopy, and this typically takes at least three years. Large trees resume vigorous growth after about one year for each inch of their diameter. The roots of a fully grown tree will extend two to three times its height.

Water Stress

• When transplanted trees are stressed by a lack of water, their roots grow more slowly, their rate of photosynthesis decreases, and they’re more susceptible to infection by insects and disease. Throughout its first growing season, a transplanted tree relies heavily on water in the root ball. The moisture in the root ball is a fraction of what the roots received before transplanting and is small compared to the loss of water evaporating through leaf pores, called transpiration. When a tree’s roots are confined to a ball, they dry quickly. Two days after it is watered, a root ball can be dry enough to reduce the ability of root tips to absorb water and stop new root growth. To prevent water stress, water your transplanted tree regularly.

  Make more efficient use of rainwater and lessen your time spent watering: Fashion a 2-to-3-inch rim of soil in a circle 2 to 3 feet larger than the diameter of the transplant hole. Fill this shallow catch basin with 2 to 3 inches of bark mulch or other coarse material - keeping it away from the trunks and stem of your transplant. Maintain this rainwater basin for one year after transplanting.

Root ball Size

• When you buy a tree for transplant, choose one with the largest possible root ball. The stored reserves in the roots get the tree through its first year, so the larger the root ball, the greater the odds for success. Look for at least 9 inches of root ball for each inch of caliper of deciduous trees and 8 inches of root ball for each inch of caliper for evergreens with needles. Arborists use the term "caliper" for the width of a tree; a caliper is the width of a tree measured 6 inches from the ground. Thus an evergreen transplant with a 3-inch caliper should have a root ball 24 inches wide.

Other Factors

• The roots of transplanted trees naturally grow slower in colder climates and more rapidly in warm climates. Large trees with correspondingly large root systems take longer to become established than small trees. Roots of trees grown in containers take longer to establish, but they are less likely to suffer any significant root damage at transplanting. Trees transplanted from burlap bags or from field soil establish faster than trees grown in plastic containers. The best time to transplant a tree is when it is dormant with no visible growth. This should be at least six to eight weeks before summer heat or freezing winter weather.