Trees are susceptible to a wide variety of different types of diseases and fungal problems that cause symptoms ranging from cosmetic injury to plant death. Knowledge of symptoms, preventive methods and diagnostic treatment prepares the home gardener for any problems that arise. Consider culture and care requirements when planting trees in the home landscape for vigorous plants capable of resisting and fighting disease.
Many factors affect tree health including care, culture, pests and disease. Recognize disease by knowing what types of symptoms to look for and the questions to ask. First ask yourself if you have implemented the optimal care for your plant or whether any environmental concerns have arisen. Research your tree and determine potential common diseases and fungal pathogens. Look for the following red flags: yellowing or discoloration of leaves, swollen plant parts, bumps or cankers (dead plant tissue), early leaf drop, fruiting bodies like mushrooms on plant surfaces or damaged leaves, fruit or flowers, according to the Iowa State University Extension. All of these symptoms point to the possibility of disease.
Fungi invade trees and cause disease. Fungi are disease pathogens that often spread sporadically; spores are disease particles that are easily transported by wind and rain. Fungi generally need extended periods of moisture to germinate during which infection occurs. Look for the appearance of mold, mildew or fruiting bodies like mushrooms or shelf-like growths on the trunk of your tree. While the presence of one mushroom may simply cause a cosmetic problem, more severe fungus issues, like root rot, destroy root systems, decay wood and kill trees, according to the University of California IPM Online.
Care and Prevention
Tree diseases and fungal pathogens usually attack weakened trees before they attack healthy trees. Prevention through proper care is the easiest way to avoid tree disease. The important factors include soil, water and sun exposure. Soil comes in all levels of porosity with varying degrees of drainage; poorly drained soil traps water, creating a breeding ground for fungi. Different soils have varying pH levels as well; most trees prefer either acid or alkaline soil. Determine watering needs like whether your tree needs consistent irrigation or if it is drought tolerant to prevent dehydration and nutrient deficiencies. Though many trees prefer full sun exposure, some need partial to full shade to prevent damage from direct sunlight.
Some diseases, including certain fungal infections, cannot be cured once your tree is affected. If preventive chemicals are available for your tree, fungicides inhibit the formation of fungal infections if applied before pathogens take hold. Contact your local county extension agent for a list of diseases common to your tree in your particular region and apply preventive fungicides when appropriate.
Both natural and chemical treatments help rid trees of disease. Before using chemicals to treat an existing problem, remove and destroy all affected plant parts from the tree and from the ground below to prevent the spread of disease. Sanitize pruning tools between each cut and from one plant to the next to prevent disease transfer; avoid creating wounds through which pathogens enter. As with preventive fungicides, certain chemical control methods treat tree diseases after symptoms develop. Determine whether a chemical control is available for your tree and the tree disease. If the fungicide is not available for home application, contact a professional for further assistance.