Numerous fertilizer application methods are available. The best method for a given situation is based on the soil and foliar analysis. competing vegetation, soil type, desired effects and other considerations, such as the use of property and location of groundwater. No one method is best suited for all situations.

The most frequently used, easiest and least expensive method is broadcasting a granular fertilizer on top of the soil. A spreader is calibrated to deliver the desired amount of fertilizer over the root zone. After the application, the area must be watered to dissolve the fertilizer and wash it off the grass and into the soil. This method has the advantage of being inexpensive, using simple nutrients taken up by grass and other plants and thus not available to the trees. Smaller and more frequent applications need to be applied when the grass is present.

Another method of applying fertilizer is the spraying of a liquid, water-soluble fertilizer. This method requires a tank and spray mechanism, which can be as simple as a hand sprayer to as complicated as a large tank sprayer mounted on a trailer. It has the disadvantage of requiring more expensive equipment to apply. An advantage is being quick to apply after the desired formulation is mixed.

In order to eliminate nutrients being taken up by grasses and other shallow-rooted plants, fertilizers may be applied directly into the root zone. One method of this type is soil injection. Fertilizers are mixed in a tank similar to the above method, then a soil probe is pushed into the soil to a depth of six to twelve inches. These application points are spaced on a grid pattern that is two to three feet apart. The advantages are that the fertilizer is injected directly into the root zone where it is needed, applying water at the same time and adding air spaces by breaking up compacted soils. This method has a disadvantage of requiring expensive equipment and the potential of rapid leaching.

Another method of applying fertilizer directly into the root zone is the drill hole method. This method uses a portable drill with a bit two to five inches in diameter. Holes are drilled in a similar pattern and depth as the liquid injection method. Granular fertilizer and a soil amendment, such as peat moss, perlite gravel or sand are placed in the holes. A broadcast application of fertilizers helps to eliminate the patchy effect visible when the grass is present. This method also has the advantage of aerating the soil but requires the location of utility lines before starting. A third method of applying fertilizer directly into the root zone is through the use of fertilizer spikes. These spikes are two to three inches long and made of a compacted fiber impregnated with fertilizer. The fertilizer is released slowly as the spike disintegrates in the soil. This method requires very few tools, but is expensive when treating large areas and slightly compacts the soil where the spike is inserted.