Fall is a very good time to transplant trees and shrubs. It might also be a very economical time to do so, as many nurseries and stores are having closeouts on them at the end of the season.
Richard Jauron of Iowa State University Extension says that early spring and late fall (after leaf drop) are the best times to transplant deciduous trees. Evergreens are “…most successfully transplanted in early spring and late summer (late August to mid-September).”
It is preferred to water new transplants in the container two or three days before transplanting to aid in having moist roots for transplanting. This will help minimize damage to the roots.
When digging the hole for a transplant, the University of Minnesota Extension indicates that it is preferred to dig a hole that is one or two feet wider than the width of the container. The hole should be wider at the bottom than at the top. This will allow the roots to grow fairly easily, and provide an area for unwrapping any roots that are in a spiral.
If the roots in the new tree are in a spiral around the soil ball, they are root bound and problematic. You do not want your roots to go around each other or the base of the tree, as this can “strangle” the base as the roots grow larger in diameter and make it more difficult for the roots to expand outward. If root bound, separate the roots so that they extend outward from the base of the new tree.
When backfilling the tree hole, amend poor soils with organic material or loamy topsoil by forking the original soil with the amending soil. Peat is not recommended for backfilling in clay, as it tends to draw too much water from the clay. Do not completely fill with amendments, as the area should only be considered as a transition to the soils around the hole.
After you have dug the hole and located your tree/shrub in the hole, start backfilling the hole with dirt up to a few inches at a time and lightly packing (firming) the soil each time. I like to add a little water each time to aid in firming the soil around the roots and removing air spaces. Avoid adding more than a half-inch to an inch of soil above the root flare. Leave a slight depression at the top of the backfill to aid in collecting/ keeping the water during watering or during rain.
The University of Minnesota Extension states that there is no need to stake a shrub, but if you are transplanting a tree, you should have two- (or three) four-foot stakes about 10 inches from the tree. A soft rope or tape designed for staking trees is preferred to tie the tree to the stakes. The stakes should be removed after about one year.
For the first week or two, you should water your tree or shrub transplants every day, as the roots have typically been severely reduced or restricted. For the next month to three months, water every two to three days -- or until the ground is frozen.