Commercial lawn fertilizers can be time released, which are best used on already established lawns, or slow releasing, which release nutrients for up to three months. A third type of fertilizer is called a soluble, and is often added to the lawn on a monthly or weekly basis, followed by hand watering. Regardless of the type of commercial lawn fertilizer you use, make sure that it contains the three basic ingredients for lush, green growth.
Phosphorous, designated on fertilizer bags as "P," is essential for proper root development. The University of Vermont Extension Department of Plant and Soil Science states that a balance of phosphorous is necessary for proper root development, and is usually designated as the second number in fertilizer ingredients, such as 5-3-4. That means five parts nitrogen, three parts phosphorous and four parts potassium.
Nitrogen, the first letter in most lawn fertilizer formulas and designated with the letter "N," is essential in promoting growth of lush, green lawns. Nitrogen puts the green in your lawn in the form of chlorophyll, vital for the process of photosynthesis. Nitrogen is also valuable in encouraging new growth.
Potassium, denoted by the letter "K" (the chemical symbol for potassium) on lawn fertilizers, is responsible for health and disease resistance in lawns. Potassium also contains components that encourage grass blades to grow tall and strong.
Most lawn fertilizers also contain varying amounts of micronutrients, which include manganese, zinc, iron, boron and sulfur. Manganese is also vital for photosynthesis, and zinc is necessary for reproduction and growth. Sulfur helps to balance the pH level of soils and break down nitrogen, while iron is directly related to chlorophyll and the deep green of a healthy lawn.