Ask anyone who has spent hours in their yard meticulously planning and cultivating what a tree disease can do to your landscape. They will probably tell you about the frustration and expense of having to replace a tree, or the stress of finding the cause and cure for the disease that afflicted the tree. One of the best ways to maintain a healthy landscape is by proper planning and prevention of tree diseases.
A tree disease occurs when an outside bacterium enters the tree causing major harm and often taking over the tissues which supply necessary water and oxygen. In order to treat the tree, you'll first need to discover the source of the problem. There are two types of tree diseases, infectious and noninfectious; both can cause critical harm to trees.
Infectious tree diseases are diseases that can be transmitted from one tree to another. Bacteria, viruses and fungi that feed on chlorophyll, which can manifest as mushrooms, are all potentially deadly sources of infections.
The most widely seen infectious diseases in trees include:
- Powdery Mildew Tree Disease affects many trees and presents as a powdery white substance on the leaves.
- Sooty Mold Tree Disease is a fungus that lives and feeds on the leaves and in the sap of some trees.
- Verticillium Wilt Tree Disease is a soil disease that travels through the roots to the branches and leaves, causing wilting.
- Canker Tree Disease describes a group of fungi attacking a tree causing dead spots on the trunk.
- Heart Rot Tree Disease consists of fungus infecting an exposed tree, or one with an open wound.
- Root and Butt Rot Disease, a fungal disease, will weaken the roots and damage the butt of the tree.
Noninfectious tree diseases are caused by a non-living agent, and are not transmitted from one tree to another. However, these infections can weaken the tree and cause infectious diseases to take over. Extremes weather changes, chemical contamination, drought and excess salt are known to cause noninfectious problems. High temperatures and not enough water will cause leaves to scorch and fine roots to die. Too much water will cause oxygen deficiencies, which lead to reduced growth and even injury to the leaves. In both cases, the conditions are prime for a fungal infection, inviting disease to enter.
To the outside observer, symptoms of the noninfectious disease may resemble a pest or fungus problem. While this may be part of the problem, the underlying cause is usually from a noninfectious source.
Before planting trees, an essential first step is purchasing disease-resistant seeds and saplings. Also, research on accurate transplanting techniques and maintaining sufficient watering and fertilizer habits will go a long way in the health of a tree. Good maintenance practices and proper identification of the illness are the key to a healthy, attractive landscape.