Understanding Tree Canker Wounds

Posted on: 27 April 2016

If you have trees on your property that have protruding and woody growths, then your trees are most likely affected by cankers. These growths may or may not be a sign that the tree needs to be removed. If you are concerned about the growths on your trees, then keep reading to learn about the different types of cankers that may be forming and how you can save your trees from eventual removal. 

Understanding Cankers

Cankers are wounds that form on trees. These wounds may be open or closed varieties depending on the cycle of the canker. If it is open, the wound will appear dark in the middle and the wood may look rotten and soft. Bark will not cover open wounds, and there may be some brown gum or yellow-colored sap around the canker. Closed wounds will be covered with bark, and you are likely to see a large wood protrusion where the canker has formed. The protrusion will be the spot where the tree has grown tissues over and around the affected area. This will be a healed canker. 

Most cankers form when fungi or bacteria attach to broken or damaged areas of the tree. Torn bark across the trunk, a broken limb, and dents in the tissues can all allow cankers to form. Insect activity around the tree can lead to them as well. Cankers typically will not cause sudden and unexpected tree death. This is especially true if annual or perennial varieties form. These types of growths occur when the tree is dormant. This means you are likely to see formations on the tree during the cold weather months in the fall and winter. Once the tree is active again in the spring, the tree will be able to build healthy tissues around the wound. In the case of perennial cankers, the wound is likely to form again in the fall. A circular canker pattern will be seen on the tree. This only becomes an issue once the canker becomes quite large and takes over a big area of the trunk.

If your tree has something called a diffuse canker, then you may need to seek out assistance for tree removal. Diffuse cankers occur when a fast-moving fungus infects the tree and leaves open wounds. Since the fungi moves fast, the wounds cannot heal themselves. The result will be numerous dead spots around the tree where bark has been damaged. If you see widespread sores, then diffuse cankers are likely. 

Keeping Trees Healthy

Trees that are unhealthy are most likely to be attacked by bacteria and fungi that cause cankers. Keeping trees healthy is the best way to prevent cankers and to reduce damage when they do appear on your trees. If you see the formations, then fertilize the soil in the spring so your tree can successfully form tissues over the wounded area. Fertilizers with a good amount of nitrogen are best for trees, but you will also need to make sure that the additive has other macronutrients as well. Look at labels and choose a product that contains phosphorous, sulfur, potassium, magnesium, and calcium. 

Spread your fertilizer over the surface of the ground where the established tree is growing. The product should be spread over the entire root structure of the tree. The roots are likely to spread out about 12.5 feet from the base of the tree at most. Make sure the fertilizer is placed on all sides of the tree about 12.5 feet from the center. 

Once you have added fertilizer to the tree, make sure to look for signs that it is not getting enough water. Dry soil, yellow leaves, and curled leaves are all signs that the tree needs moisture. Place a sprinkler by the base of the tree and water the tree several hours a day, starting in the morning. The tree will have enough water once the leaves start to flatten out. To find out more about tree services, there is more info here.