As long as the ground is workable and not frozen, you can plant a shade tree. However, planting a tree in the spring or in the fall is more ideal. In fact, fall just before or after the leaves have changed colors is the best time since the tree will have time to become established and grow new roots before the ground freezes. It will then be ready to grow the next spring. Before planting, it's a good idea to contact your local utilities company to make sure there are no underground lines where you plan to dig.
Dig a hole that is twice as wide as the tree's root ball or container. Dig to a depth that is about ½ to 1 inch shallower than the root ball or the depth that the tree is currently planted in the container.
Roughen up the sides and the bottom of the hole with your shovel. This will help the roots penetrate the soil as they grow.
Remove the tree from the container, if applicable. Use a hammer to tap the sides and bottom of the container to help loosen the tree. Grab the tree from the bottom of the trunk, if necessary, to help in this step. If the roots are growing in circles along the outside of the soil, take a utility knife and cut four even vertical slits along the sides to free the roots of this growing pattern.
Prepare a tree that is balled and burlapped for planting, if applicable. Take out the staples and any twine or strings. Always remove plastic or non-biodegradable burlap completely. On the other hand, biodegradable burlap does not have to be completely removed. At a minimum, loosen it to check that the roots are not growing in circles. If so, free them with your hands of this pattern. Also, bend roots pointing up to the downward position.
Set the tree in the hole so that the top of the root ball is about ½ to 1 inch above the ground. Extend any loose roots out. The roots should not go up the sides. If so, cut them to fit the bottom of the hole. For bare rooted trees, first make a small mound at the bottom of the hole to guide the roots over and down the mound.
Backfill the soil, tamping it down as you go to get rid of any pockets of air. Keep adding soil until the root ball--which is slightly above ground level--is covered. Then, slope the soil down around the root ball until it meets ground level.
Water the tree with about 3 to 4 inches of water. Then, set a hose a by the trunk of the tree and turn the water on to a slow trickle. Leave it there for about an hour.
Cover a 3 foot perimeter around the tree with about 2 inches of organic mulch, such as bark or wood chips.