How to Fertilize Your Lawn

All plants need nutrients, which they usually absorb from the soil they are planted in. To maintain a healthy lawn with a strong root system and lush green grass, you need to ensure that the soil in your yard contains enough of the nutrients your grass requires. The type of fertilizer you need will depend on soil conditions, climate, and the kind of grass you are growing.

Test your soil

A soil test will give you the information you need to choose the right lawn fertilizer. You can find out your soil type and the pH of your soil, and also get a detailed breakdown of which nutrients are lacking.

In Florida, soil samples can be sent to the UF/IFAS Extension office for testing. The landscape and vegetable garden test is available for private homeowners. Contact your local Extension office to find out how to collect a soil sample and send it for testing.

Choosing the right fertilizer for Florida lawns

Your soil test results should give you information about the proportion of nitrogen, phosphorus and potassium in your soil. Understanding what these three key nutrients do will help you to choose a suitable fertilizer for your lawn:

• Nitrogen promotes quick growth and helps to keep your lawn green and vibrant
• Phosphorus encourages the growth of a strong root system
• Potassium provides nutrients and helps grass to resist disease

When you look at different types of lawn fertilizer, you will see that each is labeled with an NPK ratio, expressed as three numbers. These numbers tell you the content percentage of nitrogen, phosphorus and potassium in the fertilizer.

To choose the best fertilizer for your lawn, you'll need to take into account the particular needs of the type of grass you are growing as well as your soil test results. In Florida, our soil usually has high phosphorus levels already. If you are experiencing problems with root growth and suspect a phosphorus deficiency, carry out a soil test to confirm nutrient levels before using a phosphorus fertilizer.

Fertilizer ordinances

Before you make any decisions about your lawn fertilization schedule it's important to check for local ordinances. Many counties in Florida prohibit the use of certain fertilizers during the rainy season. This is because heavy rainfall can wash the fertilizer away before it is absorbed into the soil.

The excess nutrients, particularly nitrogen and phosphorus, contained in lawn fertilizer can cause serious problems for Florida's aquifer and ecosystems if they are washed into lakes or creeks or down the drain. Your city or county may have ordinances to restrict what types of fertilizer can be used.

Restrictions may include:

• Content of fertilizer (typically nitrogen fertilizer may be restricted)
• Time of year fertilizer can be applied
• Distance to be kept from bodies of water
• Regulations for cleaning up spills
• Grass clippings may need to be kept away from hardscaping and storm drains

To avoid having a negative environmental impact, be sure to follow any relevant ordinances. The Florida-Friendly Landscaping Project has an app to help you find any ordinances that apply in your location.

Summer-season fertilizers, without any nitrogen or phosphorus content, are a possible alternative if you feel the need to fertilize your Florida lawn during the summer months.

When to fertilize your lawn

In Central Florida, homeowners tend to choose warm-season grasses such as Bahia grass or St Augustine grass. These grass types thrive in a warm climate and grow most actively during the hot summer months.

Lawn care experts recommend fertilizing warm-season grasses during the spring, as the active growing season begins. Many Florida counties permit the use of at least 50% slow-release nitrogen fertilizer from March through June.

Calculating the right amount of fertilizer

Before you purchase your fertilizer, you need to work out exactly how much you will need. Begin by calculating how many square feet your lawn takes up. Measure the length and width of your lawn in feet, then multiply these numbers together to find out how many square feet your lawn covers. Making an accurate calculation of your lawn's square footage is important, as applying too much fertilizer can be harmful to your lawn and to the environment.

If you have carried out a soil test, you will know what fertilizer to choose because the results will tell you what is lacking in your soil. If not, you can choose a fertilizer based on the needs of the type of grass you are growing. Bear in mind that you should not apply more than one pound of nitrogen per thousand square feet of lawn area.

Applying fertilizer to your lawn

The most common application method for a pellet fertilizer is to use a drop spreader. This device has a hopper that holds the fertilizer, with a hole at the bottom that you can open or close as you wheel the spreader over your lawn.

Take care when filling the hopper. Spills could mean a small, concentrated patch of fertilizer that might damage your lawn. For the same reason, be careful not to over-fill. You don't want fertilizer spilling out as you go!

Lawn care experts recommend beginning by walking the perimeter of your lawn to create header strips. You can then push the spreader slowly up and down the lawn, making parallel strips.

The header strips provide a convenient turning point. Be sure to close the hole in the hopper as you turn around, to avoid a concentration of fertilizer in one spot. Walk at a steady pace to keep the fertilizer application rate even.

Once the lawn is evenly covered, take care of any spills by sweeping them up and disposing of the excess fertilizer. Spills or excess must not be rinsed into the water system. This is important to prevent the fertilizer from contaminating lakes, streams, or groundwater.

After fertilizing, water your lawn sparingly. You want to ensure that the pellets of fertilizer are washed down to soil level so that they can be absorbed. However, you don't want to use so much water that the fertilizer is washed away.

Greening your Florida lawn during summer

Since many Florida counties have ordinances preventing the use of fertilizer during the summer months, here are some tips for other ways to maintain a lush, green lawn during our warm season:

• The first step goes way back to when you first establish your lawn. Choose a suitable warm-season grass that thrives in Florida's hot climate. A native or well-adapted grass will be much easier to keep looking its best.
• Use water effectively. Be careful not to over-water, as this can cause browning. Pay attention during the rainy season, as you may not need to irrigate during these months. Under drought conditions, water sparingly, preferably first thing in the morning so the water can be absorbed into the soil before it evaporates.
• If you want to green a Florida lawn over the summer months, consider applying iron sulfate rather than a nitrogen-based fertilizer. This should help to develop a deep, dark green color.

These tips should help you to take good care of your lawn, keeping your grass green and healthy. If you don't want to fertilize your lawn by yourself, contact your local professional lawn care service or lawn fertilizer service for support. Maintaining your lawn on a regular basis is the best way to promote healthy growth and keep your yard looking lush.

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