Another two weeks of rain, tornados, and wind have caused trouble throughout Iowa since the last newsletter. Where will it end?? Trees suffering severe injury as a result of these storms aren't always the luck of the draw. Certain tree species are much more susceptible to damage than others. For instance, silver maples, Siberian elms, willows, green ash, and hackberry can suffer considerable damage. Sugar maples, Norway maples, basswoods, and oaks sustain only light damage. Other factors that play a part in storm damage include age and maintenance history of the tree. Large old trees, improperly pruned trees, and those trees with narrow crotch angles can be particularly susceptible to damage. Severe injury can reduce the life of a tree. Wounds caused by storm injury can provide an entrance point for decay organisms and insects. Wounds can also disfigure the tree or ruin its intended function.
If your tree has been damaged, carefully examine the extent of damage. Give immediate attention to trees that are hazards to people or property. If a power line is involved, utility company personnel are the only ones who should be working in the area. After the elimination of hazardous situations, individual tree care can be assessed. Unfortunately, assessment is a judgement call with a large gray area. Severe splitting of the main trunk or an injury that removes more than 1/3 of the bark around the tree is a wound that few trees can survive. Broken tree tops are also severe injuries. Injured trees take time to heal. Repair methods are geared toward assisting the tree in healing as quickly as possible. Most repair work involves pruning. Use correct pruning techniques to minimize the size of the wound and avoid flush cuts. Remove large, uneven stubs by pruning back to an undamaged side branch. Wound dressings are not recommended. Cabling and bracing may be appropriate if the cost involved can be justified. This method of repair does not save trees with extensive structural damage.
After deciding the treatment necessary, the next decision is who will do the work. Many of us do the work ourselves or hire a tree care specialist. For minor damage on small trees a homeowner with knowledge of proper pruning procedures, access to proper equipment, and desire can handle the job. Severe damage is better left to someone who specializes in this area. When contracting repair work out, both the homeowner and the tree service professional must clearly understand the work to be done and the cost involved. If your area has received considerable damage, repair professionals may be heavily booked. It may take some time before they can get to your site. It's important to keep people away from potentially dangerous situations until the necessary work is completed.
If tree replacement ends up being your only alternative, select tree species and cultivars with a sturdy reputation. Excellent maple selections include black, Norway, red, and sugar. Oak species include white, swamp white, bur, and red. Linden (both American and littleleaf), thornless honeylocust, and ginkgo are other possibilities.
This article originally appeared in the July 14, 1993 issue, p. 114.