Every year more than one million trees are planted on public and private properties throughout North America, these are not the trees are not planted as a part of a reforestation project, they are the trees that we use for personal and community ambience. Of these trees, less than 50 percent will survive more than two years.
Shock From Transplanting:
The greatest transplanting shock comes from the loss of the tree’s root system that occurs when the tree is dug up at the tree farm. Placing the tree in shock makes it much more vulnerable to disease, insects, drought and other potential life threatening situations. The transplant shock lasts until the root system is fully replaced to the level it was prior to being removed from the tree farm. Most trees that die after being transplanted do so during the period of time prior to restoration of the full root system. Although there is no method of transplanting that will guaranty that a tree will not die, regular care and good gardening practices, for a three-year period following the transplant, will definitely improve the trees likely hood of survival.
Transplanting and Tree Roots:
A healthy trees root system grows horizontally, even the main structural roots grow horizontally from the base of the trunk rather than vertically. Ask anyone who has tried to plant flowers near the base of a tree. The root system will generally extend to an area well beyond that of the visible branch coverage. The thicker roots which are located close to the tree trunk do not absorb water and nutrients, those roots are the fine roots and they are usually located within a four to ten inch depth below surface grade. For proper tree growth there must be a balance between the foliage of the tree and the root system.
In most cases when a tree is removed from its original location more than 95 percent of the root system is left in the ground. That leaves only five percent of the system to supply 100 percent of the required water and nutrients to the tree. Hence, the trees root system cannot supply water at the rate that the crown is capable of dissipating it. Without the required water, the tree cannot produce an adequate supply of carbohydrates, and it makes the tree susceptible to disease, resulting in the death of the tree.
Regeneration of Root Systems For Transplanted Trees:
Regeneration of the root system is the primary key to ensure that the tree does not die due to the transplanting. It is critical that the visible part of the tree remains healthy during the period of time that it is regenerating its root system. Initially the root system will receive the necessary carbohydrates to induce growth from those stored in the trunk and branches of the tree. In order to ensure that the tree remains healthy after transplanting it is of critical importance that the tree continues to produce adequate levels of carbohydrates throughout the growing season, and even more important during the first year after the transplanting has occurred.
Some people believe that the best way to ensure a healthy tree after transplanting is to prune the tree so that the root system does not have to provide as much water and nutrients. This is an incorrect procedure! If you leave the tree as delivered it will aid in supporting the growth of the root system. The only pruning that should take place is cutting away any damaged or broken tree branches or limbs. To assist the root system you must continue to supply water as ambient water will be insufficient to promote a healthy root system.
There is no defined time frame for the root system to re-establish itself as it dependent on the size of the root ball, soil conditions, and climate. Bigger trees loose more root system when originally removed than smaller trees. Hence, it will take longer for a big tree to create its root system than a smaller tree, providing all other factors remain constant.
Tests have indicated that for a tree with a one inch diameter trunk it may take from four to seven years for the root system to be back to 100 percent efficiency, depending on the type of tree, climate, soil and moisture. A ten-inch tree could take as long as 15 years to replace its entire root system.
The growth of the root system and new upper tree growth is dramatically reduced post transplant. You may however notice a lot of new twigs the first year after transplanting. This is because the buds were formed prior to the tree being removed from its original location. Following the first year, the amount of new upper tree growth will be directly related to the growth of the root system. This provides a visual indication of how root growth is proceeding - few new buds, little root growth.
Planting Techniques and On-Going Care:
The tree you choose and the location you are going to place it must be a match. Picking the wrong tree for the sites soil conditions will mean that the root system may never fully regenerate itself. If you choose the right tree for the location and provide the proper care, there is no reason to believe that the tree will not survive and grow. Tree type, soil conditions, and care will definitely reduce the likely hood of death due to insect attack and disease.
Carefully consider the size of the hole needed for the tree you are about to plant. Most individual have a tendency to dig a hole that is correct in depth but incorrect in width. The width of the hole should be a minimum of three times the diameter of the root ball. If you are planting in an area that is always wet, the tree can be planted so that a third of the root ball is above the final grade. By doing this the majority of the root system will remain above soil that is water saturated.
Use the soil removed from the hole to fill in the area around the root ball. If you are adding an organic soil additive then the area that this new mixture fills should be large enough for a 3 to 5 year root growth.
Watering seems to be the area that confuses the vast majority of individuals. There appears to be many different theories on the amount of water needed and how often to apply that water. This could be because depending on where you live soil and the associated climate will make a dramatic difference to the amount of watering needed. Soil moisture is critical to your new tree’s survival, to little and it will die of drought, to much and you will saturate the soil, removing the space required for oxygen. The consensus of opinion is that a transplanted tree needs one-inch of water a week for the first year. It is best to check with your local nursery for exact recommendations for your area.
Three to four inches of wood or bark chips placed over the area that has been excavated for the tree will maintain the moisture in the soil and control soil temperature swings. Mulch will also inhibit the growth of weeds and grass, both of which compete for the moisture and nutrients in the soil. It is not recommended that you replace any sod that was removed to dig the hole nor is it wise to plant flowers at the tree base during the first year.