Whether you've grown a tree from seed in a container or you've misjudged the size of a landscape tree, you'll want to ensure your tree plenty of room to mature by removing it from its container and planting it in the ground. The best times to do this are spring and fall, since hot summer weather can sap the tree's energy. Either time works in temperate areas but gardeners who experience winter frost should transplant container-grown trees in the spring to avoid stressing trees before winter.
Choose a location for your container-grown tree that offers the tree plenty of room to grow. Mature trees vary widely in size, so consult a tree guide or ask someone at your local nursery to determine how large your maple, oak, evergreen, fruit tree, linden, birch or other tree will grow in spread and height.
Dig a hole that's twice the size of the tree's root ball, which you can estimate based upon the size of the container holding the tree. Jab the bottom of the hole with your shovel to break apart the soil; this helps the transplanted tree set its roots.
Remove your tree from its container. Grasp the trunk of the young tree and pull it up. Some trees will slide out. If your tree sticks, work the container soil with a small rake or shovel to loosen it. Be careful not to jab the tree's roots. When you've loosened the soil, try again to pull up the tree. Continue working the soil until the tree comes free.
Examine the tree's root ball. Untangle and unwind any tangled or circled roots. Circled roots are especially likely in container trees; if left circled, they will eventually choke and kill the tree.
Place the tree in the hole once you've tended to the roots; check to see it's vertically straight. Spread the tree's roots out with your fingers. Ensure the tree is planted at the same depth as it was planted in the container.
Fill in the hole with soil, taking care not to compact it. Once you've mounded soil around the base of the tree trunk, water the newly transplanted tree until the ground becomes saturated. This will compress the soil and remove air bubbles naturally.
Layer mulch on the ground in a 3-foot ring around the newly planted tree. This helps the tree retain moisture near the soil.