Purpose

• The purpose of fertilizers is to feed your lawn. There are also specialized fertilizers that will protect your lawn from insects and fertilizers that will kill weeds in your lawn. Fertilizer is what gives your lawn that healthy green color as well as growing a thick, dense carpet of grass. If a lawn is healthy it will be better equipped to fight off disease and insects.
  
  

Features

• There are three components of lawn fertilizer. They are nitrogen (N), phosphorus (P) and potassium (K). These elements are shown as a three-digit number on the fertilizer bag; for example, 12-6-8 or 30-10-10. These numbers are the percentage of the substance in the fertilizer. The first number is always nitrogen, followed by phosphorus and potassium. Out of these three elements nitrogen is the most important for grass as it helps the grass to grow strong, dense and thick. It also gives it that lush green appearance. Potassium encourages root growth.
  
  

Types of Nitrogen

• When choosing a fertilizer, another important fact to know is that there are two types of nitrogen: fast-release nitrogen or controlled-release nitrogen. The advantages of a fast-release nitrogen content will be that the grass will green up quickly; the disadvantages are that it may cause a large flush of growth and may burn the lawn. In general the controlled release nitrogen fertilizers are better for lawn applications. A controlled-release nitrogen content will provide a uniform growth and tends not to burn the grass. However, controlled-release nitrogen fertilizers tend to be more expensive.
  
  

Specialized Fertilizers

• Besides the straight fertilizers there are specialized fertilizers. One of these is the "weed and feed," killing any weeds within your lawn while promoting growth to the grass. Denser grass will eventually leave little room for weed growth. Other specialized fertilizers are summer and winter fertilizers as well as starter fertilizers for newly seeded lawns. Summer and winter fertilizers focus on a specific problem related to that season. For instance, the summer fertilizer application has elements in its content that protect the lawn from insects.
  
  

Choosing Fertilizers

• Fertilizers also come in different forms such as granular, liquid, synthetic and organic, each of which has its advantages and disadvantages. For instance, granular fertilizers are most generally used due to their ease of application and cost. Liquid fertilizers are easy to apply as well; all you need is a hose to attach the spray bottle of fertilizer to. Yet, they are usually more expensive and you need to apply them more often. Synthetic fertilizers require repeated applications, and organic lawn fertilizers are more labor intensive and the odor may be offensive, since they are made from manures.