By Mike Albers
The care you give damaged trees now can impact tree survival. Here are some do's and don?ts for dealing with storm damaged trees.
1. Do inspect trees for damage. Deal with hazardous trees first. Hazardous trees are those that have a target ? something that will be damaged if the tree or part of the tree falls. Targets include people, buildings, cars, etc. Trees that won?t damage something when they fall can wait until hazardous trees have been dealt with.
2. Do watch for detached branches that are hanging in the tree, loosely attached branches and split trunks. These should be taken care of quickly to avoid injury or damage. Broken but firmly attached branches that pose no immediate danger can be pruned later. Trunks split down the middle should be removed. Cabling or bracing is only recommended for a very valuable tree and must always be done by a professional arborist and inspected annually.
3. Do seek professional help from a forester or arborist when deciding which trees to remove. However, severely damaged trees are obvious. If a large branch or stem has been pulled out or broken, taking 40% to 50% of the circumference of the main trunk with it, the tree should be removed. If more than 50% of the live branches in a tree crown have been broken or gone, the tree should be removed. Leaning trees with evidence of recent root lifting or soil movement should be removed. Trees with cracks that affect 50% or more of the main stem should be removed. Trees with less damage may also need to be removed especially if they also have columns of decay, cankers or other defects. A professional can help you decide whether to try and save a tree.
4. Do use proper pruning techniques. Do not flush cut branches. Prune to preserve the branch collar, the swollen area at the base of a branch. Do not leave stubs. Limit pruning at this time to making the tree safe while keeping as many live branches in the crown as possible. Removing branches creates wounds and you want to create as few wounds as possible while the tree is under stress.
5. Don?t top trees. A topped tree looks like it got a butch haircut. Topping removes a large portion of the leaves the tree needs to produce food. Topped trees are more susceptible to insect and disease pests. Branches left after topping easily become decayed and create future hazards. Branches that develop after topping are often weakly attached and easily break off during winds.
6. Don?t remove living trees unless necessary. Tree removal should be a last resort. A professional forester or arborist should check a questionable tree to make sure it is not hazardous and is worth saving. Even if it doesn't look good now, it can rebuild crowns and look good again in a year or two.
7. Don?t be rushed by bargains. Anyone with a chainsaw and a pickup can cut a tree down. But, improper pruning or removal can cost you more money from damages.
8. Don?t use climbing spikes on a tree you want to save. Climbing spikes damage the tree and make it more susceptible to insect and disease problems, especially decay.
9. Don?t try to save a leaning tree ? it most likely has broken roots and won?t survive. If it does survive, it often becomes a hazard. Mature trees rarely survive attempts to pull them back into place. Very young trees may survive if they are gently pulled back into their vertical positions. Be sure to press out air spaces in the loosened soil, water the entire root system twice each week in the absence of rain. Cover the root area with two to four inches of wood chip mulch. Stake the tree for the first year to prevent it from falling again. Tree staking is usually not recommended when planting trees but is of a tree that has blown over.
10. Don?t use rope, wire, wire in a garden hose or any narrow band of material when staking a tree. These will injure the trunk and could kill the tree. Use instead a broad strap or other fabric at least one inch wide. Date the staking and remember to take it down next year.
11. Don?t fertilize damaged trees. Fertilizer can inhibit a tree's ability to recover. It creates a fast-growing, green tree with lots of leaves, but if the tree's roots have been damaged, the root system may not be able to support the extra growth. A fertilized tree may be more susceptible to drought.
12. Don?t use paint or wound dressing to cover wounds. These materials may actually interfere with the natural wound sealing process. However, in the metro area and southeastern Minnesota only, a latex-based wound paint is recommended for pruning cuts on oak trees during May, June and July to prevent oak wilt.
13. Do water stressed and damaged trees. If conditions become dry, trees will need ½ to 1 inch of water per week during the growing season. Be careful not to over-water trees, especially on heavy clay soils. Check the soil under the trees. Water only if the soil is dry. Watering will help trees repair and rebuild and will help them defend themselves from insect and disease pests that attack damaged trees.
14. Do use mulch. Mulch can help stressed trees by helping to conserve water in the soil, keep the soil cool, prevent soil compaction, and encourage more root growth. Wood or bark chips make the best mulch and should cover an area at least 2 to 3 feet in diameter around small trees (larger area for larger trees) with a depth of 2 to 4 inches. Pull the mulch back at least 4 inches from the trunk. Mulch against the trunk encourages rodents chewing on the bark and can also encourage stem decay.
Further information on proper care of trees can be obtained from your
local DNR, consultant forester or county extension offices.