Planting a new tree where a tree was removed can be done if the old tree, including the roots, is completely eliminated from the old location. This must be done because the microbes and bacteria that help in the decay process taking place in the old tree's root system, use the available nitrogen in the soil. If all the nitrogen is already tied up, the new tree will grow slowly, remain stunted or even die. Also, if the old tree died of disease and a large portion of the tree is left underground, then the new tree could catch the disease and die, especially if it is the same kind of tree.
Choose a good quality native tree that is suitable for your area to plant in the new location. A list of trees recommended for your planting zone can be obtained from your local county extension office. If the old tree died of disease, avoid planting the same kind of tree in its place.
Plant your new tree in the fall. Although trees purchased in containers can be planted anytime of the year if given sufficient moisture, it is best to plant most trees in the fall so the roots can get established before warmer weather arrives the following summer.
Remove as many of the existing tree roots from the old tree or remaining stump as possible, using an ax and shovel or whatever tools are necessary. It is important to remove the roots that still exist underground from the previous tree that was planted in the same location where you are planting the new tree.
Plant the new tree in the old tree's location once all the old plant material and roots are removed. Dig a hole with the shovel that is twice as wide as the root base of the new tree so the roots can spread out. The depth of the planting hole should be deep enough so the new tree is planted at the same depth it was planted in the nursery container or previous location.
Fill the planting hole with the same soil removed from the hole unless it is full of old wood from the previous tree. If that is the case, add soil from another nearby location so the soil is similar to what was removed from the planting hole. Mix water with the dirt as you refill the hole to avoid creating air pockets around the roots of the new tree.
Add a 1- to 2-inch layer of mulch around the root base of the new tree leaving an inch of space between the trunk of the new tree and the mulch. This will prevent rot or mildew from traveling to the trunk of the tree from the decaying mulch.