Even trees that are selected for hurricane resistance can have a hard time adjusting to worst-case scenarios. Proper tree maintenance and handling can improve their survival in severe storms. Here are some tree maintenance tips for high-wind areas:
- Let trees adjust to the wind environment. It has always been thought that newly planted trees had to be tightly staked and guyed in place. Research has shown that this practice prevents the tree from naturally adapting to wind loading. If trees need to be staked, stake and tie the tree loosely where the stem can move and bend in the wind. Continue to loosen the ties so no girdling will take place. The tree will continue to grow and adjust to its new environment.
- Practice proper pruning techniques. Branches should be cut before they become larger than one-inch in diameter on young trees. The branch collar should not be damaged when pruning. Prune and thin trees to give them a lower center of gravity and to lessen leaf mass.
- Eliminate co-dominant branches. Co-dominant branches have an area of included bark which is subject to split and cracks. Prune forked branches and branches that arise opposite each other on the stem early in the tree’s life. Cut one side off early to prevent losing the whole tree later if it splits in a storm. In trees with opposite branching patterns, such as ash or maple, proper branch training is essential for a long-lived, storm-resistant tree.
- Keep trees as healthy as possible. Timely watering and proper fertilization are essential for tree health in the urban setting. Healthy, vigorous trees adjust more quickly to changes in the environment, are more wind firm and react more effectively to damage.
- Do not overfertilize trees with nitrogen or overwater the soil. These practices can increase crown surface area and/or decrease the rooting area. It is a good practice to mulch around trees with a 3- to 4-inch mulch layer properly laid out.
- Eliminate lopsided crowns. Prune branches to produce a reasonably symmetrical crown. If more than 70 percent of the crown is on one side of a mature tree, consider tree removal and replacement.
- Guying and bracing branches are last ditch efforts when a tree has to be saved in spite of itself.
- Remove or treat pest problems like insects, diseases and branch cankers to minimize potential damage. Apply fertilizer evenly on the mulched and unmulched surfaces out to about 1.5 – 2 times the canopy diameter.
- Keep the tree growing upright with one main stem. Prune away branches that compete in height with the main stem. Eliminate branches with tight or narrow crotches. These are potential weak spots.
- Install lightning protection systems on historic or rare specimen trees.