The process involved in transplanting a number of green ash trees is the same process as transplanting any deciduous tree. Trees may need to be moved if they are located in an inconvenient location such as under a power line or have grown up from seed and are too close together. Because ash trees produce a large amount of seed, small seedlings are easily relocated by digging with a shovel while minimally disturbing the root system. Then they can be transplanted elsewhere. For larger trees, up to 10 feet tall, another method is used that takes a year to complete.
Push a shovel into the ground 10 inches deep in a semicircle 18 inches from the trunk of the ash trees you want to move in the fall. This is to cut half the roots at the base of each tree to prepare for transplanting the next fall. The reason for this is that feeder roots are located at the ends of the main roots. When you cut the main roots, it forces new feeder roots to form closer to the tree trunks so the trees can survive transplanting the next fall, when the other half of the roots are cut to remove the trees from the soil.
Water the trees that had their roots cut over the summer if they show signs of drought stress. Do not overwater as the roots that were cut will rot because they aren't developed enough consume an excess amount of water.
Cut the remaining roots of the ash trees to be transplanted in a semicircle 18 inches from the base of the tree 10 inches deep thenext fall. Before removing the tree, tie a piece of plastic garden tape on the north side of the tree so it will be transplanted with the same north-south orientation. This prevents sun or cold damage to the side of the tree that is not accustomed to certain temperature extremes. Dig under the tree as deeply as possible to avoid damaging the least number of roots. Once the trees are released from the soil, pull them onto a tarp by grabbing the dirt and root ball and not the trunk of the tree. Grabbing and pulling the trunk of the trees damages the area where the roots are connected to the trunk. Never pick up a tree by its trunk for this reason.
Drag the tarp with the trees on top or lift them into a wheelbarrow or truck to move to the new location. Spray the roots with a light spray of water to avoid letting them dry out.
Dig the new holes for the ash trees that are big enough to accommodate the root systems. Dig the holes deep enough so the trees are planted at the same depth they were in their previous location. After placing the trees in their new planting holes, fill with native dirt mixed with water to seal the dirt around the roots to avoid the formation of air pockets that can dry out the roots. Cover each root base with a 1-inch layer of mulch after planting. Leave a 1-inch space between the trunk of the trees and the mulch so mildew cannot spread from the mulch to the tree.