Tree seedlings that have lived several years and are growing under comfortable cultural conditions, develop and thrive on a careful, natural balancing of leaf surface and root growth. For an undisturbed, healthy tree, the root system is normally very shallow. Even the major structural roots grow almost horizontally.
With an adequate supply of water and nutrients, a seedling or sapling will continue healthy growth until roots become confined by a container or other barrier. In most cases the root system extends out and beyond the spread of the branches and a considerable portion of the roots are cut when the tree is moved.
What Is Transplant Shock?
Transplanting a tree seedling or sapling can be the most stressful time in it's entire life. Moving a tree for its original comfort zone to a new location should be done under the right conditions while preserving most of the life-supporting root system. Remember, when transplanted to a new location, the plant has the same number of leaves to support but will have a smaller root system to supply water and nutrients.
Major stress-related problems can often result from this inevitable loss of roots, especially feeder roots. This is called transplant shock and results in increased vulnerability to drought, insects, diseases and other problems. Transplant shock will remain a planting concern until the natural balance between the root system and the leaves of the transplanted tree is restored.
Of all newly planted trees that do not survive, most die during this very important root-establishment period. The health of a tree and its ultimate survival can be assured if practices that favor establishment of the root system become the ultimate gold standard. This takes persistence and involves regular care during the first three years following transplanting.
What Are The Symptoms Of Tree Transplant Shock?
Symptoms of tree transplanting shock are immediately obvious in trees that are moved in full leaf or when leaves form after the replanting. Deciduous tree leaves will wilt and if corrective steps are not immediately taken, may eventually turn brown and drop. Conifer needles turn a pale green or blue-green color before turning brittle, browning and dropping off. These browning symptoms begin first on the youngest (newest) leaves which are more delicate and sensitive to water loss.
The very first symptoms, in addition to leaf yellowing or browning, can be leaf rolling, curling, wilting, and scorching around the leaf edges. Trees that are not immediately killed can show dieback of the branch tips.
Things To Do To Avoid Transplant Shock
So, when you transplant your tree, a very delicate balance is altered. This is especially true when transplanting "wild" trees from yards, fields or woods. Your chances for success are improved if you root prune the tree a year or two before the actual transplant. This simply means to sever with a spade the roots around the tree at a comfortable distance away from the trunk.
Root pruning causes tree roots to grow in a more compact form which in turn allows you to get more of the total root system when you dig up your ball. The more roots you get, the better your chances will be for tree survival.
Don't be tempted to prune tree branches and foliage! A healing, growing root system is very much dependent on a full contingent of leaves. For this reason, pruning transplanted trees to compensate for root loss is not recommended.
Do: Leave the entire top intact to favor rapid development of a supporting root system.
Don't: Forget to provide supplemental watering which is critical for avoiding moisture stress.
Keeping foliage moist is a great way to prevent transplant shock. Spritz water on tree leaves to cool and reduce water loss from foliar surfaces. Anti-transpiration sprays such as WiltPruf or Foli-Gard are also effective in reducing water loss. But remember that these materials are latex/wax-based and can temporarily interfere with food production within the leaf. Do not overuse these anti-desiccants and always follow label directions.
The best way to reduce transplant shock - only plant hand dug or bare root trees when they are dormant!