What Kind of Lawn Fertilizer Do I Need?

Reasons to Fertilize

• When you fertilize your lawn, you're providing it with several nutrients that it needs: nitrogen, phosphorous and potassium. When the lawn gets these nutrients, it has a richer color and is able to recover better from stressful conditions. Fertilizer can also help prevent invasions from weeds and diseases that could otherwise have a negative impact on the health and quality of your grass.

Reading a Fertilizer Label

• When you're choosing the type of fertilizer to use, read the label. There will be three numbers on the label, which correspond to the percent nitrogen, phosphorus and potassium content, in that order. For example, a label of 16-2-12 means the fertilizer contains 16% nitrogen, 2% phosphorous and 12% potassium.

Determining Amount of Nitrogen Needed

• Nitrogen amount is the most important factor in choosing a fertilizer. A general recommendation for the amount of nitrogen to use is 1 lb. per 1,000 square feet. So if you know the percentage of nitrogen in the bag, you can determine how many pounds of fertilizer you need to equal 1 lb. of nitrogen. For example, a 5 lb. bag of fertilizer that is 20% nitrogen means 1 lb. of the bag is nitrogen. That bag could cover 1,000 square feet of grass.

Fast-Release vs. Slow-Release Nitrogen

• Fertilizer comes in fast and slow release-nitrogen versions. Fast-release nitrogen will provide fast growth and will keep nitrogen in the soil when temperatures drop. However, it can also burn patches of grass or cause overgrowth. If you want fast results for low cost, fast-release fertilizer is a good choice. If you use controlled or slow release fertilizer, you'll have less chance of burning your grass and will get more uniform grass growth. However, it is slower to act and more expensive. It also doesn't always work well in the cold. But if you want to prevent damage to the grass, your climate isn't too cold and you don't mind paying more, use a slow-release nitrogen fertilizer.

Use a Fertilizer Designed for Your Purpose

• Fertilizers will have different levels of nitrogen, phosphorous and potassium depending on what they are designed to do. Read the label to determine what the fertilizer is designed to do for your lawn. For example, a fertilizer designed for winter will have more potassium while fertilizers intended for brand new, seeded lawns will have higher levels of phosphorous.