It is very important when transplanting trees to be aware of the season. Trees lose most of their water through their leaves. So you should move these trees when they do not have leaves. In other words, the best time is while the tree is dormant. Another timing factor to consider is how old the tree is. Tree saplings over 6 inches would be a good choice, but remember the bigger the tree is, the bigger the root system it has, so more mature trees are going to be much harder to move, and have a greater chance of going into shock.
If you are going to move a tree in the late winter, make sure that you move it late enough that the ground is no longer frozen. Oak trees are one type of tree that does very well with late winter transplanting.
Moving and transplanting in the springtime is by far the best time to transplant trees. They will handle the shock so much better if moved correctly. The tree will still be dormant, and once you transplant it, then it will have perfect temperatures and rains to help it along.
Some trees fair fine if you transplant them in early fall, one type that prefers this time is the evergreen tree. If you are going to be moving evergreens in the fall, be sure to give yourself enough time so that your tree will be able to spend at least three weeks in its new home before winter starts. This method works best if your evergreen was shipped from an area that is colder than yours. If you live in a very cold area and your evergreen is coming from a warmer one, then you will want to wait to transplant this tree in early spring and let it have more time in the soil before winter hits it.
You will not want to, under any circumstances, transplant a tree in the middle of the summer. The tree will have all of its leaves so it will lose a great amount of water, and the weather is far too hot. Your tree will most likely go into shock and die, and then you will be missing out on its beauty.
Now that you are ready to transplant your tree, here are a few other tips. Make sure the soil where you are going to be placing your tree is dug prior to moving your tree. Follow the correct procedure for digging up your specific tree. Keep your tree well-watered during the process of moving it. It may take up to a year for a tree to recover from being transplanted. The larger trees go into shock easier than the smaller trees during transplanting.