Oak Tree Root Damage Treatment

Causes of Root Damage

• Oak tree root damage is often caused during construction. Installing utility lines, a sidewalk or the home's foundation may cause injury to an oak tree's root system. Piles of dirt underneath an oak tree during a construction project can smother roots. Other causes of damage include compacted soil, drought and transplanting shock. Gardeners may hit a surface root with their lawnmowers. Once damage has been inflicted, diseases such as oak wilt enter the wounds in the root system and wreak havoc on the oak's health.

Pruning

• Oak trees with damaged roots must have their branches thinned to reduce the amount of water they need. To pick out branches to thin, examine the oak tree. Look for branches that appear damaged, diseased or dead. Also, choose branches that are rubbing up against each other or casting shade inside of the oak tree. Thin a small branch by making a pruning cut next to the branch collar. The branch collar is the natural swelling that attaches a branch to the main trunk. Cut large branches by making a cut one-third of the way through the diameter of the branch from underneath 4 inches from the branch collar. The second cut must go all the way through the top of the branch 2 inches from the branch collar. The last cut is at a 45-degree downward angle next to the branch collar.

Irrigation

• Damaged oak trees need adequate water. Without enough water, oak trees cannot properly heal. To water your oak tree, place soaker hoses underneath the dripline of the tree. The dripline is the area directly underneath the outermost branches. Apply 1 inch of water a week. Water must be able to soak down to the first 12 to 18 inches of soil. Spreading a 3- to 4-inch layer of mulch around the oak tree will help retain soil moisture.

Fertilizer

• Fertilizing damaged oak trees provides them with enough nutrients for healthy root development. It is extremely important to avoid fertilizing an oak tree with excessive amounts of nitrogen. Nitrogen promotes foliage growth, which the damaged roots cannot support. Gardeners use 2 lbs. of slow-release fertilizer with an NPK amount of 5-10-5 per an inch of the tree's diameter. Wrapping a tape measure around the tree gives you an idea of how much to apply under the dripline.