How to Apply Tree Fertilizer

Growing trees should be fertilized throughout the year. The greatest amounts of fertilizer containing Nitrogen-based fertilizer should be applied during the early spring and summer months. There is no need to remove the mulch that is placed around the tree. Scatter or drop fertilizer under the tree's drip zone and avoid touching the tree trunk with the material.

• Water the fertilizer into the soil as this prevents fertilizer burn injury to the roots. Stick with a higher ratio of nitrogen fertilizers unless the tree is deficient in Potassium or Phosphorus; this can be detected when performing a soil test. nitrogen, phosphorus and potassium rates of 18-5-9, 27-3-3, or 16-4-8 are good choices to use.


• Organic fertilizers come from plant and animal sources. They have a slower release of nutrients as they need to decompose by breaking down into the soil. They are easy on plant roots but take longer to find, are more expensive and the least harmful. These types of fertilizers are less exacting when applying. The best ones are cottonseed meal, bone meal, manure and chicken litter.  It is best to read the label for application methods and the right amount to use.


• Inorganic fertilizers are inexpensive and used most frequently to fertilize trees. The inorganic nitrogen-based tree food sources are sodium nitrate, ammonium nitrate and ammonium sulfate


• General purpose fertilizers are complete with nitrogen, phosphorus, and potassium. These fertilizers can be used but it is very important to not overuse them. Use high-ratio nitrogen products unless a soil test suggests a lack of other nutrients. These fertilizers come in slow release liquid or water soluble for application. Read the label for application rates


• Remember soil amendments. The value of most organic materials is the change brought to the soil structure. Chemical fertilizers have no physical affect on soil structure. Peat moss, leaf mold, pine bark, saw dust and stable manure can improve the soil while adding nutrients. The soil amendments increase the fertilizer and the water holding capacity of many soils. Mulching, a very important soil amendment, aids in strong root development.