A leaning tree may be the result of several different occurrences. If the tree was planted unevenly, for instance, or if the soil was not tightly packed around the base, the tree will continue to lean as it grows. Constant wind may also cause trees to lean while the roots are still developing, or the roots of nearby plants may grow beneath the tree, pushing it in one direction. Whatever is causing your tree to lean, you can make it stand upright.
Drive two stakes into the ground on the side of the tree that is opposite the direction in which the tree is leaning. Place the stakes approximately 1 foot apart.
Place two lengths of wire around the tree that are long enough to wrap around the tree and reach the stakes. Put a pad against the tree where each wire touches it to keep the wire from direct contact with the bark. Pull the wires so they are taut, and wrap the ends of each wire around one of the stake to provide support to the tree.
Remove the soil at the base of the tree until you see the roots. Dig outward from the base, removing soil so the roots are visible. Digging a hole approximately 10 times the diameter of the tree should provide the necessary freedom to move the tree, according to website ThisOldHouse.com.
Push the tree upright. If the tree is large, pushing it upright may require several people. Have someone stand on the opposite side of the tree to pull in the slack created in the wires attached to the stakes when the tree is pushed upright. That person will wind the slack around the stakes to hold the tree in place.
Cover the roots with soil again, and pack the soil firmly to help hold the tree in place. Use the back of a spade to firm the soil, and press down on the soil with your feet to further compact it.
Keep the stakes and wires in place for three or four months, and keep an eye on the tree as it continues to grow. If the tree begins to lean, you may need to add more stakes to keep it fully upright.
Upright leaning trees while they are young for the best results. If nearby plants are the culprit, it may be a good idea to relocate the other plants, giving the tree a 5- to 6-foot clearance on all sides to prevent further intertwining of roots.