Plant Maintenance and Disease Management
We all know that if we maintain a healthy lifestyle, we can prevent or avoid diseases that would be more severe if we didnít take good care of ourselves. Is this also true for our trees and shrubs in the landscape? Are trees and shrubs that are provided with good care more able to withstand diseases? Well, yes, this is true for the most part. And while one doesnít expect their trees and shrubs to exercise and get plenty of rest, we want them to have the right dose of minerals and to eat and drink well. So, how can tree and shrub care minimize disease?

Before the tree can eat, it must make its own food. This means converting energy from the sun into food energy. This process, called photosynthesis, requires plenty of sunlight, water, air, and of course leaves to manufacture food. If the tree makes ample amounts of food, it will have the energy reserves needed to fight off infections such as canker diseases. Tree and shrub maintenance practices that enhance food production include many good growing practices. For example, provide water during dry periods of the growing season. Mulch trees or shrubs with composted organic materials to help them retain soil moisture and to reduce competition. Trees and shrubs donít need much fertilizer, so fertilize them only if they are showing deficiencies. Prune for good health, but do not top trees or prune too much away because they need leaves to make food. Prune away nearby vegetation which blocks the sunlight to more valuable plants.

Can one provide too much tender loving care to trees and shrubs? Yes, too much water leads to root rot disease. If established trees and shrubs receive an inch of rain each week, there is no need to water more, but when dry weather comes, apply the one inch. Can one over-mulch? Yes, mulching too deeply can lead to excessive surface rooting, provide a harbor for damaging rodents, and allow too much moisture on the tree trunk. Furthermore, some mulches can change the soil acidity over time which can lead to mineral deficiency. So, learn about your soil and the mulch you use. Too much fertilizer can cause trees and shrubs to grow too rapidly. Over-fertilized trees and shrubs are often more susceptible to diseases. Fire blight and powdery mildew, for example, thrive on trees and shrubs with too much fertilizer. If your lawn is already being fertilized, the trees and shrubs usually do not need any additional fertilizer. Drastic pruning such as topping opens up trees to wood decay fungi that weaken and destroy the trees.


Over mulched roots

Thus, good tree and shrub maintenance practices will result in a healthful lifestyle, and hopefully, greater resistance to destructive plant diseases.