Fertilizing Your Summer Lawn May Do More Harm than Good

Fertilizer is a powerful tool that can help your Florida landscape thrive — if used appropriately. However, if applied incorrectly, it can not only harm your lawn and plants, but also the environment.

Here in Florida, fertilizing during the summer months can do more harm than good, due to the heavy rains we receive. Summer rains don’t actually help fertilizer get to our plants roots, like so many people think. In reality, these heavy rains either wash fertilizer away or through the plant roots – with some of it going right into our streams, rivers, bays and the Gulf of Mexico. These are some of the water sources that we rely on for drinking water.

You can help keep our drinking water sources clean by following these tips if fertilizing your lawn this summer:

  • The University of Florida recommends no more than 2 to 5 applications of fertilizer on St. Augustine grass during the year. Once in late March-early April and more spread throughout the year. So the rainy season could come off your list!
  • Choose slow-release products. Look for fertilizers with slow-release nutrients. They should include potassium and little or no phosphorus.
  • Add some iron to your lawn. An application of iron, readily available at most garden centers, will keep your lawn green during the summer without excessive growth. As an added bonus, you won’t need to mow it as much! And if your lawn begins to yellow, that is a clear sign that it may need more iron.
  • Keep fertilizer off hard surfaces. If fertilizer gets spilled on a hard surface (like a driveway), sweep it up and dispose of it. Fertilizers can wash into storm drains and from there into a nearby water body. No matter how much you fertilize the pavement, it just won’t grow!
  • If you spill fertilizer on the lawn, collect whatever you can. It may be easier to simply water it into the lawn, but this can result in the excess nutrients leaching through the soil and into the groundwater.
  • Never fertilize within 10 feet of any water body. This area needs to be a “no maintenance zone.”
  • Don’t fertilize before a heavy rain. This is a good reason not to fertilize during the rainy season at all but if you must, look for a period of low or light rainfall to fertilize.
  • Plant Florida-friendly plants. Plants that have adapted to Florida’s hot, humid climate need less water, fertilizer and chemicals year-round.

If you live in Manatee or Pinellas counties, or the City of Tampa, there is a ban on applying fertilizers containing nitrogen or phosphorous from June 1 – Sept. 30. But there are still ways to keep your lawn healthy without these types of chemicals. Look for fertilizers with “0” as the first two numbers on the label (0-0-6). These do not contain either nitrogen or phosphorous and are safe to use during the summer.

For more tips on how to take care of your landscaping this summer that are good for both your lawn and the environment, visit the Hillsborough, Pinellas or Pasco County UF/IFAS Extensions.