Buying young trees and transplanting them into your yard and garden is the easiest way to start growing trees at home, because growing trees from seed takes a much longer time to start seeing results. Container or potted trees are commonly found in local garden centers, while bare root trees are frequently sent from mail order catalogs while they're in their dormant state, and will not suffer from shock too easily.
Transplant When Dormant
The best time to transplant deciduous trees--those that lose their leaves in the winter--is while they are dormant. This causes less stress on the tree and doesn't interrupt their foliage or flowering stages. Since bare root trees are in their dormant state when shipped, they should be planted as quickly as possible after receiving them. Evergreen trees don't go dormant, so transplant those from pots or other yard locations in early spring.
Select Site Carefully
Before transplanting a tree, select a new site that meets all its needs. Take height into consideration if power lines are around for example, and make sure you're not selecting a planting spot that will grow too close to the foundation of your home. Don't select naturally moist spots for planting a tree that prefers drier soil, and make sure the spot you select has the right amount of sunlight for the type of tree you've chosen.
When transplanting a tree, dig a hole large enough for the tree's roots, but not so deep that it will sink into the ground as the newly dug dirt settles. Dig a hole that's about twice the size around than the pot your tree is in, or twice the size of the existing rootball if it's not in a pot. The depth of the hole should only be as deep as the tree rootball or pot.
Make a small mound of soil in the bottom center of the newly dug hole, and sit the tree roots on this mound. Make the mound large enough that the top of the rootball is even with or slightly higher than the top of the hole. If the roots are clumped and tightly held together, loosen them gently and spread them out over the mound. Add soil back into the hole a little at a time, gently tamping it down to remove air pockets. Be careful not to tear or damage the tree roots.
Once your new tree has been transplanted, it will need several months to become fully established to its new environment. Give it 5 to 7 gallons of water each week during the first several months, and surround it with a deep layer of natural mulch such as bark or wood chips.