Cankers: Bad for Humans and Trees

Donna Green, Family & Consumer Sciences Educator, Ohio State University Extension Canker sores are small, shallow ulcers that appear in the mouth and make eating and talking painful. They tend to be genetic; my mom and we kids used to suffer through them. If you've ever had one, you know what I'm talking about.But trees can get canker "sores" as well, and for them it may not be a temporary inconvenience. Cankers can end up killing a tree.Cankers start through a variety of ways; the primary one being a fungus. It enters the tree and eventually grows between the bark and the wood, killing the tree. However, cankers can also be caused by damage from weed eaters, lawn mowers, chemicals, insects, or other irritants in the environment such as hail.Cankers will appear on a tree as small dead areas on the bark, stems, branches, and/or twigs. If they are on the bark, the color will look distorted and the bark may have an indentation.The canker then becomes a magnet that makes the tree vulnerable to bacteria, fungus and insects. Young trees have an especially difficult time recovering from cankers.But the healthier a tree is, the more likely it is to survive canker disease. Trees that are weakened by temperature, drought, or poor nutrition are more susceptible to canker diseases.How Do You Treat Canker?Preventing cankers from getting a toe-hold in the first place is the best method of protection. Choose to plant only native or well-adapted species from our growing region. Tree species best suited to a northern Ohio climate will adjust more quickly to the soil, sun exposure, and environmental conditions of this area.Next, try to reduce stress on the tree. It is the best and most effective protection against canker disease. This means watering, feeding, mulching and pruning to help to keep the tree as healthy as possible.If your tree develops canker disease, you will have to remove as much of the fungi as possible to prevent the infection from spreading. Prune the area only during dry weather, and use a sterilized cutting tool.Pruning should be done late in the dormant season (late winter/early spring) without damaging the surrounding bark. Do not prune during wet weather, or from mid-August to leaf drop. This is when canker and wood decay fungi are the most active.Arbor DayArbor Day, the day we celebrate trees, occurs on the last Friday in April, which this year is April 27. The first Arbor Day was celebrated in Nebraska. A pioneer named J. Sterling Morton moved his family from Detroit to Nebraska in 1854, and one of the first things the family did upon relocation was to plant trees, shrubs, and flowers. Nebraska at that time was wide-open spaces, and they desperately needed trees for windbreaks, fuel, building materials, and shade.Morton's passion for trees transcended throughout the state and eventually the nation. He is rightly credited with starting the first Arbor Day celebration. He knew the value of trees, and I admire how he was able to inspire fellow Nebraskans, and later all Americans, to grow and protect them.I can't stress enough how important trees are to our communities. They contribute to our environment by providing oxygen, improving air quality, conserving water, preserving soil, and supporting wildlife.Trees take decades to reach maturity, so do what you can to prevent losing one.