Once a tree drops its leaves they have prepared themselves for winter. They go into a "hibernation" mode if you will. Fall and even winter is a great time to plant trees. As long as you can dig the hole, you can plant the tree. When planting a tree becareful not to dig the hole deeper then the root flare. Root flare, is the part of the trunk that flares out. The tree should not look like a telephone pole going into the ground. You might need to pull some dirt away to see this part of the trunk. Also the hole should be atleast 1 1/2 times the diameter of the root ball. You cannot dig the hole to wide! Please try hard not to do any pruning for about 2 growing seasons. The tree is stressed when transplanted and you do not want to create any more stress with pruning. Once the leaves come out in the spring make sure you water the tree throughout the first year until leaves drop. You want to give the tree enough water that the soil is soft but not to wet. It usually is couple of gallons of water a day.