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How to Fertilize Trees


Your trees are a thing of beauty that needs to be cared for — a necessary part of that care is proper fertilization. Trees have been growing on their own since long before the science of tree care was developed, but using modern fertilization methods will help you to achieve the desired lush and hearty result. Before you dash out to the local supply store, let’s take a look at how to fertilize trees, what types of fertilizer to use and when you should fertilize your trees.


Why Should I Fertilize my Trees?


First, you might be wondering why you should fertilize your trees in the first place. By providing your trees with nutrients, you’ll enable them to grow strong and healthy, and build up their ability to ward off pests and other environmental stresses. Think of it as similar to eating a healthy diet and taking your vitamins — by feeding your body properly, you’re better prepared to fight illness.


When to Fertilize Trees


In places such as Colorado and other Northern temperate climates, the best time to fertilize your trees is from fall to mid-spring. These are the times when any nutrients that are absorbed are used more for things like root development and disease prevention instead of going toward feeding new growth, as would be the case in late spring and summer. If you wait to apply fertilize until the summertime, it will go directly to feeding the new leaf growth rather than building up the root system and disease resilience, which is the main goal of fertilizing trees.


Where Should I Apply the Fertilizer?


Fertilizer needs to be applied wherever your trees’ root systems have spread, which means don’t just apply it to the base of the tree. Root systems usually extend out past the spread of the branches of a tree, so in general, you’ll want to apply fertilizer from the trunk all the way out to several feet past where the cover of the branches ends. When applying fertilizer to your tree, make sure to spread it evenly across the surface rather than applying it in too concentrated of an area — over-application in one spot can “burn” the roots and cause harm to your tree.


What Kind of Fertilizer Should I Use?


There are two components of fertilizer: macronutrients, such as nitrogen and phosphorus, and micronutrients, such as iron and magnesium. The type of fertilizer you’ll need to use varies widely depending on the type of trees you have — what is good for one tree can prove harmful to another tree. Identify the specific type of tree you’re fertilizing, and then do your research on which type of fertilizer will be best suited to the task.


Rather than risk applying the wrong type of fertilizer, contact our Fit Tree experts here at Fit Turf to schedule an evaluation or to request a quote. Our team of specialists will also be able to talk to you about different treatments to apply at any time of year to help you protect your valuable trees and shrubs from pesky insects.