How to Pick Lawn Fertilizer

Test the soil pH with a kit available from your local garden supply store. Dig a hole and place soil samples in the sterile containers, then send the samples to the lab on the address label.

Evaluate the results of the soil pH test to determine the best fertilizer for your yard. Fertilizers with ammonium, sulfur and ammonium sulfate will decrease the soil's pH. Magnesium and calcium can increase the pH.

Buy a fertilizer high in nitrogen for an established yard. Check the label on the bag; the NPK amount stands for nitrogen, phosphorus and potassium. Nitrogen is inexpensive compared to phosphorus.

Choose a fertilizer high in phosphorus for a new yard. Phosphorus helps grass establish roots and promotes growth.

Purchase fertilizer high in potassium for lawns damaged by winter. Potassium helps grass resist diseases and strengthens cell walls.

Choose between slow-release and quick-release fertilizer. Slow-release fertilizer comes in granular pellets that must be applied to your lawn with a spreader. It's easier to apply than liquid fertilizer, because you can see where you are spreading the pellets. Quick-release liquid fertilizer comes in a bottle that you attach to a garden hose. It must be applied to the lawn every two to three weeks.