Pruning Trees to help prevent Storm Damage PRIMARY RESOURCE: ”Some Illustrations, excerpts, Power Points and photos are by Edward F. GilmanPhD, Professor, Environmental Horticulture Department, IFAS, University of Florida.” (contact

The Shade Tree Commission recommends that you hire a New Jersey Certified Tree Expert (CTE) to do all Pruning. A CTE is identified by a three number Code, such as CTE#222. A CTE is licensed by the State of New Jersey as tree Expert

Administered by the New Jersey State DEP, the Certified Tree Expert title is considered one of the most prestigious in the nation. Less than 400 CTEs are active in the State of New Jersey today.

Pruning objectives: Reduce risk of failure – minimize storm damage Promote human safety Allow for safe passage Increase sun penetration to the ground Maintain health

Types of Pruning Root pruning: Never Root Prune a tree without professional guidance. Only Removing a Girdling Root should be done on a regular basis. Pruning of the Canopy. Only Crown Cleaning and Crown Thinning should be done. NEVER, ever TOP a tree. It only creates more problems and weakens the tree. It is the moral sin of crown pruning.

Remove Girdling Roots Girdling Roots are roots that circle the base of the tree. Girdling Roots can weaken the root system and the trunk which can cause tree failure in a storm.

Stem girdling roots Roots that circle around the base of the trunk Girdling root

After removing girdling roots

Stem girdling roots may cause trees to topple Location of girdling roots. Notice that there are few supporting roots on this side of the tree.

NEVER ROOT PRUNE A TREE! Root pruned trees are more likely to fail during a storm. Root pruning destabilizes the tree and causes disease and decay to enter the root system. Root pruning is prohibited on Borough trees, including street trees during sidewalk repair without a permit from the Shade Tree Commission.

Root pruning can cause…

THIS !

Start Crown Pruning when trees are Young Starting to prune trees when they are young will make pruning easy and allow the tree to easily heal. Pruning young will prevent problems when the tree is older. Pruning older trees can weaken the tree.

Inaction can cause structural problems Young trees are easier to fix Older trees are more challenging to treat Codominant stems with bark inclusions

Poor structure such as codominant stems often cause branch failure in storms

Common mature tree problems codominant stems included bark dead branch water sprouts broken branch sucker dead branch decay

Recommended Pruning Techniques 1. Crown Cleaning: Crown Cleaning is a process of removing problematic branches from a tree's crown. 2. Crown thinning: Removal of select branches from the inside of the tree to “open” the tree canopy. 3. Using these two techniques together will produce a happy and health tree that is less prone to failure.

Crown Cleaning Crown Cleaning is a process of removing problematic branches from a tree's crown. Branches that are dying, diseased, crowded, or posing danger to life or property are removed, and very little of the live and healthy crown is affected. Crown Cleaning can promote healthy, long-term tree growth.

Crown Thinning Crown Thinning, is removing select branches from the inside of the tree. This will reduce the amount of leaves that can act like a sail, thus reducing wind resistance. The tree will be healthier. Air circulation and photosynthesis will also be optimized. There will be less chance for fungus or other diseases to take hold. Dappled sunlight will allow having some grass beneath your trees. It will be easier landscaping in these areas with the dappled sunlight.

Crown Cleaning & Thinning will: Reduce storm damage Reduce risk of tree failure Reduce shade and allow for dappled sunlight Remove cracked weak limbs Remove Broken branches Remove branches with included bark Remove diseased limbs

Pruning can reduce damage A recent study at UF showed that pruning reduces canopy movement when trees are exposed to high winds. Not pruned Pruned

One Objective: Of Crown Pruning is to Reduce risk of failure Identify risks – Bark inclusions – Cracks – Over-extended limbs – Leaning trees – Root decay – Girdling roots Reduce conditions that could lead to catastrophic branch or tree loss. reduce

Another Objective: Reduce Shade & increase light penetration. Before thinning After thinning More light here

Pruning to: Clean Removal of dead, broken, rubbing, or diseased branches, and foreign objects. Reduces the risk of branches falling from the tree

Removed cracked branches which indicate weakness Crack

Cleaning takes care of Broken Branches Broken branches

Failure due to Included Bark

Close-up of included bark

Objective: Maintain tree health Removed diseased branches

Remove diseased branches

Before pruningAfter pruning

before after

Poor formGood form Principles of strong structure: One dominant trunk Strong branch unions Balanced canopy

Determine a pruning cycle with your CTE to maintain your tree. Pruning cycle: - more than 3-5 years = higher pruning dose - every 1-2 years = smaller pruning dose Suggested program: - At planting - Year two or three - Year five or six - Year ten - Year fifteen

Poor management Better management Your goal Single trunk Multiple trunks

NEVER TOP A TREE Topping results in the: 1-Disfigurement of the tree 2-Sprouting of weak branches 3-Promotes insects and decay 4- Compromises the Structure of the tree 5- Weakens the canopy of the tree 6-Shortens the life span of the tree 7-INCREASES storm damage potential 8-Can cause root death which destabilizes the tree

Topping trees promotes bad structure! Sprouts

Topping creates a “Sail”

TOPPING CAUSES DECAY WHICH WEAKENS THE TREE

CLOSE UP OF DECAY CAUSED BY TOPPING

If you see the word TOPPING in an advertisement … RUN AWAY!

In Conclusion Proper pruning (Crown Cleaning and Thinning) will decrease the chance of storm damage. Use a New Jersey Certified Tree Expert (CTE) to examine your tree. NEVER top the tree. NEVER Root Prune a tree. Always maintain your tree on a schedule worked out with the CTE. Borough trees require a permit