Homeowners can repair small to medium-sized evergreen trees, but it's best to use professional help for very large trees, suggests the North Carolina State University Extension. First, determine whether the tree is worth saving. Trees that have 30 to 50 percent of the trunk and main branches damaged likely cannot benefit even from extensive repair strategies and should be replaced.
If the evergreen tree has toppled over, it needs to be replanted immediately since the exposed roots start to lose moisture rapidly. If a tree has too many roots exposed, it may be damaged beyond repair. Prune and remove any damaged roots. After digging a trench around the root area to help straighten the tree, pull the tree upright with rope. Use padding under the rope to prevent possible damage to the trunk.
North Carolina State University suggests removing a few branches on recently straightened trees, as this helps to reduce wind resistance. This consequently reduces pressure on the roots and helps them establish faster. Water the tree well and regularly, especially during summer, as this is also important for root development.
After a new evergreen has been replanted and straightened, stake the tree to provide much-needed support. On a tree that is between 6 and 10 feet tall, use two 6-foot stakes planted about 2 feet away from the trunk. Three strong stakes are suggested for trees that are taller than 10 feet. Use loose, wide, nylon belts to connect trees to stakes. Make sure the belt is neither too loose nor too tight. Leave stakes in only for a couple of years.