Determining Fertilization Needs

• The best method to determine whether a maple tree requires fertilization is to test the soil around the tree. Your local Minnesota county extension service may be able to provide a soil test kit and will be able to help you evaluate the test results.
  
  

When to Fertilize

• A slow-release, granular fertilizer can be applied in the spring, if necessary. Apply when the soil is first workable before the trees start to grow in early May. If the soil is sandy, split the application and apply once in the early spring and again in mid-May.
  
  

How to Fertilize

• Apply the fertilizer according to label instructions around the root zone of the maple. Apply only as much as is required. The fertilizer should contain equal parts nitrogen, phosphorus and potassium. Excess fertilization can hinder the maple's fall color.