Choosing the proper fertilizer for a particular species of grass can be a key part of maintaining a thriving lawn. Grass fertilizers generally promote the growth of fresh grass and healthy roots in lawns by providing grass with key nutrients, such as nitrogen, phosphorous, and potassium. Lawn owners can determine the appropriate grass fertilizer for their lawn by considering the type of grass that is growing in their lawn and the season that the grass fertilizer will be applied. Gardeners also need to determine whether they prefer their lawn to be bright green for a short period of the year or have a lawn that will look healthy throughout the growing season.
The first thing to consider when a gardener is choosing a grass fertilizer is what type of grass is grown in his or her lawn. Each species of grass requires a different ratio of nutrients in order to grow efficiently. For example, lawns consisting of Saint Augustine grass should be fertilized with a starter fertilizer when new grass is planted, followed by monthly applications of 1 pound (about .45 kg) of high nitrogen fertilizer for every 1,000 square feet (about 92.9 square meters) of lawn. Most species of tall fescue only require a couple of applications of fertilizer per year and grow best when fertilized with slow-release fertilizer.
Another important consideration in determining the best grass fertilizer for a particular lawn is the time of the year that a gardener will be fertilizing his or her lawn. During the spring, applying a slow-release fertilizer in late February or early March typically will promote the growth of a healthier lawn better than using high-nitrogen fertilizers in April or May. Lawns generally require grass fertilizers during the fall that will replenish them with the nutrients that they have spent during the summer. The best grass fertilizers to use in the fall are lower in nitrogen and contain sufficient quantities of potassium and phosphorous to promote root growth in the early winter.
Lawn owners must decide whether they want a fertilizer that will promote the rapid growth of bright green grass during the peak of spring or a fertilizer that will provide their lawn with the necessary nutrients to stay healthy for the rest of the year. Grass fertilizers that are high in nitrogen will stimulate growth in a lawn and provide owners with fresh green grass, but such fertilizers do not allow lawns to develop the root systems that are necessary for them to thrive in the long term. A grass fertilizer that has a lower ratio of nitrogen and plenty of phosphorous and potassium allows a lawn to develop roots that will eventually produce natural green grass on their own.