Salvaging a Split Japanese Lilac Tree

Timing

• Environmental factors cause a tree's bark to split. The thin bark of the Japanese lilac tree makes it susceptible to such damage. Young trees or newly planted ones suffer from cracking more often than established trees, according to Cornell University. You may notice the cracks on the tree's trunk or its branches. The cracks in the tree's bark may appear during the spring or late fall months when the weather is in a constant state of flux.

Causes

• Extremely cold weather followed by a rapid thaw will make the tree's thin bark split. Sunscald on the tree's bark during the winter months will also cause splitting to occur. If the crack is from sunscald, it may not be noticeable right away. The tree will develop a split beneath the bark, but over time the bark will also break open. If the Japanese lilac undergoes a period of drought followed by excessive rain, it can exhibit a burst of rapid growth where the bark will split. Even though such a split will rarely prove fatal, the tree will benefit if you take actions that encourage it to form a callus to prevent disease organisms from entering the tree's wound.

Repair

• If you see a crack in the tree's bark, you should trace out the split with a sharp knife. Sterilize the the knife using rubbing alcohol prior to using it on the tree. Cut into the tree's bark about 1/2 inch away from the split. Run the knife all the way around the split and begin peeling away the bark around the wound. The tree will form a callus where the bark has been removed, a shield that will keep harmful organisms from entering through the wound.

Maintenance

• You should maintain the tree's health so it rapidly repairs its wound. Fertilize the Japanese lilac tree each spring using a general purpose fertilizer. Irrigate the tree regularly, especially if it's growing in a region that is warm and dry. The soil around the tree should feel moist to the touch. The tree's crack will usually close completely as the callus forms. It may have a ridge where the split and repair took place, but little else will remain of the crack. If the tree suffered from sunscald during the winter months, wrap the tree's trunk during the winter and avoid excessive pruning.