Trees that outgrow their area, or are threatening the health of other trees, may require transplanting at some point in their lifetime. Removing and transplanting a tree requires the right technique to prevent damage to the root system, trunk and branches of the tree. Correct site selection and digging of the site will determine the success of the transplant.
Determine the potential success of a transplant before considering a move. According to the North Dakota State University Extension, certain trees and shrubs cannot handle the stress involved in a transplant. Transplanting weakens the plant's immune system and may lead to disease. Young plants are more likely to survive the move. Older trees or trees that are sick or in decline may not survive a move. Certain trees have different transplant tolerances, so it is best to check with your local university extension to determine if your tree variety will survive a move.
It is integral to the transplant that the new site for the tree is suitable. Check soil texture and drainage. Heavy clay soils may not drain enough water, while sandy locations will drain too quickly. Dig a hole 18 inches deep and fill it halfway with water to establish how quickly the water drains. If the hole drains in less than 15 minutes it is too sandy. If it drains in over 30 minutes the hole does not have adequate drainage. When a hole drains between 15 and 30 minutes the soil has adequate drainage. The addition of organic material to sandy or clay soils may improve drainage, but this could take several years.
Removing the Tree
The roots of a tree must be cut with a sharp spade to prepare it for transplanting. A sharp spade inserted into the soil around the tree, 8 to 12 inches deep, three to six months before the transplant reduces the size of the roots and promotes the growth of new roots in their place. When it is time to transplant, says the University of Tennessee, dig a hole 4 to 6 inches outside the original root pruning area and uncover the root ball of the tree. Place a piece of burlap around the root ball to prevent drying, and lift the tree onto a plastic tarp for easy transport. The plant should be lifted under the root ball, not by the stem.
The new plant site requires a hole that is two to three times wider than the root ball. When the hole has a high clay content, the sides of the hole are glazed during the digging process, becoming smooth and shiny. This area requires scoring with a shovel to encourage water drainage. Plant the tree slightly above or at the same level as it was planted in the previous location and allow for settling.
The tree requires a thorough watering after the transplanting process. Once watered, it should be observed daily for drying out. When there is little rainfall, the tree requires watering every 10 to 14 days so that the top 3 to 4 inches of soil is moist. A 3- to 4-inch layer of mulch placed around the tree will help retain moisture.