Immediate Care for Storm-Damaged Trees

Author(s): Graham Herbst
 | 
Monday, August 19, 2019
A split trunk after collapsing on the sidewalk.

Trees damaged by storms require immediate attention (removing low-hanging branches, clearing from utility lines, etc.). Homeowners need to be aware of safety issues and consider the best approach for dealing with a tree they are trying to save.

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Hazard trees

Loose branches and split trunks are obvious safety concerns that should be dealt with as soon as possible to avoid injuring someone or damaging property if the branch or tree falls. Broken but firmly attached branches that pose no immediate danger can be pruned after the more hazardous branches have been removed.Trunks split down the middle are very difficult to brace adequately, and should be removed or treated by a professional arborist.

Power lines

Branches hanging over power lines are a major safety hazard. Special training is required to prune branches over power lines. Homeowners should not attempt to prune these branches. Contact the local power company or an arborist trained in electrical line clearance to have them removed.

Leaning trees

A tree is tipped over in a parking lot
Even if a tipped tree survives, it often is in danger of falling

High winds and the heavy weight of snow or ice can tip a tree over and break the roots. Trees leaning from broken roots usually do not survive. If a tree tips in a storm, it often means the tree had damaged or poorly developed roots before the storm. Even if a tipped tree survives, it often is in danger of falling. High winds and the heavy weight of snow or ice can tip a tree over and break the roots. Trees leaning from broken roots usually do not survive. If a tree tips in a storm, it often means the tree had damaged or poorly developed roots before the storm. Even if a tipped tree survives, it often is in danger of falling. Mature trees rarely survive attempts to pull them back into place after being tipped over. They should be removed and replaced with new trees. Very young trees may survive if they are gently pulled back to a vertical position. To avoid additional damage to the remaining roots, press out air spaces that may have formed in the loosened soil; water the area of the root system twice weekly in the absence of rain during the fall, spring and summer; cover the root area with 2-4 inches of wood chip mulch; and stake the tree for the first year to prevent it from falling again. Do not tie rope, wire, wire-in garden hose or any narrow band of material around the tree during the growing season. These will injure the trunk and could kill the tree as it tries to grow. Use a broad strap or other fabric at least 1 inch wide, and inspect and adjust the location of the strap weekly during the growing season to minimize injury to the bark.

Removing broken branches

The only pruning that should be done immediately is removing broken branches. Leave the fine pruning and finishing cuts until after the tree has been thoroughly evaluated. Pruning cuts made during winter months will dry out to some degree. Dieback of the inner bark around a pruning cut can be minimized if the final pruning is done just before the tree begins to grow in the spring. Have a trained arborist make the finishing cuts.

Branches that have pulled away from the trunk should be removed at the bottom of the split. Avoid causing any additional damage to the trunk. Remove loose bark but do not cut into bark that is living and still attached.

Never “top” trees. The International Society of Arboriculture defines topping as the “indiscriminate cutting of tree branches to stubs or lateral branches that are not large enough to assume the terminal role.” Topping creates serious hazards and dramatically shortens a tree’s life. Other names for topping are “heading,” “tipping,” “hat-racking” and “rounding over.”

Never use paint or wound dressing to cover wounds. These materials interfere with the tree’s wound-sealing process.

Do not fertilize

Do not assume trees damaged during storms will benefit from a fertilizer application. In most cases, they will not and the fertilizer will inhibit the tree’s ability to recover. Fertilizers can have negative effects on trees. For example, excess nitrogen in the soil will create a fast-growing, very green tree, but it will have a poorly developed root system and will be more susceptible to drought and problems from insects and diseases. Trees generally don’t need more than 1 pound of actual nitrogen per 1,000 square feet of root area per year. If you fertilize the lawn under the tree, the tree gets plenty of fertilizer already. Apply additional fertilizer only if you know the tree has a nitrogen deficiency, which is determined by a soil analysis indicating nitrogen is present at a level below 10 pounds per acre.

If damaged trees are removed and new trees are planted, do not fertilize the new trees for the first three years. Newly transplanted trees need to regenerate the 90-95 percent of the root system they lost while being dug up. Applying nitrogen at planting time may only slow root regeneration. 

Be conservative

A tree is tipped over in a parking lot
Certified arborists have the training and credentials to help you assess storm damage and develop an appropriate plan of action.

Don’t prune or remove more of a tree than necessary. Remove hazards but postpone other decisions until later. Damage may look severe, but remember why you wanted the tree—it still may be able to serve that function. If you can delay the removal decision up to a year, you may decide the tree was not as badly damaged as you thought. After just a few years, the damage becomes much less noticeable.

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