Trees in lawns usually need less, if any, fertilization.

When we think of fertilizer in our gardens, lawns and vegetable plants spring to our minds quickly. However, making a plan for fertilizing trees and shrubs is essential for their long term health.

Fertilizer Helps Your Trees and Shrubs Eat

When you add fertilizer to the soil around your trees and shrubs, you are investing in a lifetime of growth. When plants perform the process of photosynthesis to create food, they use different chemical elements found in the soil, namely minerals and nutrients. If these are not present in sufficient amounts, the process is not able to run as efficiently (or at all!) and the plant will start to suffer. Fertilization replenishes these elements and allows your plant to continue making its own food.

It is important that you do not assume that every tree and shrub needs to be fertilized on a schedule, though. They will generally need more in their early years when they are setting down roots and becoming established. If it is located in your lawn, it will already get nutrients and minerals when you fertilize your grass.

Species metabolize at different rates and too much fertilizer can actually be harmful to a plant. The salts contained in these mixtures can cause the plant to dehydrate and wither, ending up with a disorder called fertilizer burn. This problem can also occur if you are careless in your application and get some on the plant. Read the instructions for amounts and application methods carefully.

Should I Be Fertilizing My Trees and Shrubs Now?

How do you know if you should be fertilizing trees and shrubs in your garden at this time? The best way is to take a sample of soil from around your tree or shrub at the start of the season (or later, if you suspect a problem) and send it to a soil testing facility. They are usually run by the state Cooperative Extension Service and will analyze the contents of your ground for a nominal fee. In New York, Cornell University provides soil health testing. They have specific instructions on their preferred methods of taking the sample and sending it to them.

You can also watch for problems that develop and analyze the symptoms for the possibility of a nutrient deficiency. The extension service can also help you with this or you can give us a call. We will be happy to help you assess the health of your trees and shrubs to determine if fertilization is wise.

Image by F.D. Richards under a Flickr Creative Commons Attribution-ShareAlike License