Why fertilizing your trees and shrubs is often NOT a good idea

Hi,  just wanted to talk a bit about something I see a lot of homeowners do, thinking they are helping to make their trees more healthy: Fertilizing! Many of my customers are signed up on monthly lawn and tree care services, and while it may be ok for your lawn, if you are in competition with your neighbors to have the greenest lawn, its usually not beneficial for your trees. It does not help reduce tree diseases, or insects in most cases. In some cases, it may make tree diseases worse.

Studies now show that you should only fertilize trees if they are nutrient deficient, which can easily determined with a soil test. Many people believe, and/or have been taught, that a fast growing tree means a healthy tree. This has been shown now to not be true.  In their efforts to prevent tree disease,
and keep their trees in optimum health, many people fertilize their trees several times a year.
What happens when you over fertilize is the trees grow so fast they don't have time to properly develop, and form the defenses, such as internal chemical defenses they need to stop invasive tree diseases and insects. Over fertilization has also been shown to make trees less drought tolerant.

It is much better for a tree to help its growing environment in a more natural way, such as increasing the amount of organic matter in the root zone, such as by mulching leaves around the base of the trees, which generates lots of microbial activity. Or by applying 1-2" of good organic soil mulch every years or two. This is the single best thing you can do for you trees health. (Mulching). This will help increase the trees resistance to tree diseases in a natural way.

If your trees are growing within a turf area, which is getting fertilized, they are already probably getting more than they need.
So give your lawn and tree service company a call and tell them to hold off on the random tree fertilizing next spring, unless they can show you with a soil test that they need it. The soil test should show both ph level, and nutrient levels as well. Hope you are all getting through the winter well.