The granular form is sprinkled on the soil and worked in with a tiller or hand tool. The first number in a fertilizer formula is the nitrogen content. Nitrogen is used by plants for producing leaf growth and greener, lusher leaves. The second number in a fertilizer formula is the phosphorus content. Phosphorus is used by plant to increase fruit development and to produce a strong root system.
Potassium is used by plants for flower color and size.
It is also important to the strength of the plant. Before applying fertilizer to the garden, it is best to have your soil tested. This can be done with the use of reasonably inexpensive, home test kits, or by sending a sample to your local county or state agricultural agency. The soil test will tell you the level of nutrients already in the soil as well as the pH of the soil. If your test is done by your county extension service, the test results will also provide recommendations for needed additions of lime and fertilizer.