Fertilizers improve plant growth by supplying nutrients to the soil. The primary nutrients necessary for plant growth are nitrogen, phosphorus, and potassium.

On this page:

Fertilizers and amendments
Complete fertilizers
Dry vs. liquid materials

Fertilizers and amendments

• Organic amendments are not necessarily fertilizers and should not be substituted for them.
• A soil analysis will tell you what nutrients or amendments your soil needs.

Complete fertilizers

Fertilizers containing all three primary nutrients (nitrogen, phosphorus, and potassium) are called complete fertilizers. If high levels of phosphorus and potassium are already present in the soil, supply nitrogen alone. For most established lawns, nitrogen is the only nutrient that needs to be supplied on a regular basis, although it may be beneficial to apply a complete fertilizer with all three nutrients at least once a year.

• Fertilizers are formulated in different ways according to how they make their nitrogen available to grass roots.

Dry vs. liquid materials

Most fertilizers are formulated as dry materials, however there are some formulated as liquids. Liquid formulations are not normally recommended for use on home lawns because they are hard to apply evenly and need to be applied more frequently than dry fertilizers. Turf can easily become burned. They are also more expensive than dry formulations.

Always follow the directions on the package label.

Click on the underlined parts of the label for more information.