Gary R. Johnson Associate Professor Urban and Community Forestry University of Minnesota
Ben Johnson Undergraduate Research Assistant Department of Forest Resources University of Minnesota

Inventory

By keeping track of trees on your property and their condition, preventing storm failure is much easier. Create a list of “key trees and key problems.” Key trees would be those that are most important to the property. Key problems would be those that are most likely to damage or weaken those key trees.

Monitor

Check key trees regularly. When minor damage occurs, correction (such as pruning or wound “painting” on oaks during oak wilt season) may prevent it from causing extensive damage throughout the tree. If extensive damage has occurred, immediate corrective action should be applied to prevent further damage.

Proper Pruning

Pruning either corrects problems or creates them. If pruning is done improperly, it can create places for decay to enter and the wound will only increase in extent. Done correctly, pruning wounds should close over naturally, keeping decay from starting and expanding in the wound area. A general rule for pruning wounds: the smaller, the better.

Image 1: Flush cutting, i.e., cutting too far into living tissue, can provide sites of decay. Photo by Gary R. Johnson

Image 2: Leaving long stubs may also provide entrance sites for decay. Photo by Gary R. Johnson

Protection From Mechanical Wounding

Mulching, planting trees in landscaped beds, and even staking can give trees the necessary protection from mechanical injury. Wounds caused from lawnmowers and grass trimmers can promote areas of decay in the tree. Cars, snowplows, staples, and any stacked materials that wound stems and branches can cause long-term damage in a short time.

Appropriate Species

Using appropriate species in each site is extremely important. Many of the problems that homeowners face could be diminished just by using species that are native to the area or accustomed to the site conditions. For more information on tree species selection check the Texas Forest Service Tree Planting Guide at http://texastreeplant.tamu.edu.

Best Planting Practices. Planting too deep may be the most common planting mistake that leads to tree failure. Literature is available on proper planting techniques (see Fact Sheet 1.5). Most importantly, do not plant the tree too deep. The first set of roots should be just below the soil surface.

Image 3: Planting too deep hid a girdling root that caused stem compression. The stem failed several inches below ground. Photo by Diana Bolander

Image 4: Proper way to plant a tree. Illustration provided by the National Arbor Day Foundation, Tree City USA Bulletin No. 19

Image 5: Tree failure can have severe consequences–many of which can be prevented. Photo by Gary R. Johnson

Maintain Health

By watering properly and frequently, and by fertilizing when nutrients are deficient, tree health can be maintained at a high level. When trees are stressed, they become more susceptible to problems ranging from aesthetic (leaf scorch), to decay, to severe, uncorrectable damage from diseases or insects.

Assistance

City foresters, county Agrilife Extension offices, and tree care professionals are available to answer questions about tree care problems.

Summary

Planting the right tree in the right place is the first step in preventing tree damage. Proper care and maintenance of trees will also help to prevent damage.