Using Lawn Fertilizer Before It Rains Wastes Money and Pollutes Waterways

ST. PETERSBURG - Are you counting on the rain to water-in your lawn fertilizer? You may want to reconsider. Save time and money by avoiding the practice of applying fertilizer before a heavy rain.

Sometimes Florida yards need fertilizer to help keep them healthy, but applying fertilizer at the wrong time can cause water pollution. You can use Florida-friendly fertilizing practices to help protect water quality while having a beautiful lawn.

If you fertilize your lawn before a heavy rain, much of the fertilizer will be washed directly into surface water or stormwater systems that drain to our local springs, lakes, rivers and bays.

Recent studies have shown that rising nitrate levels in many local water bodies can be traced to fertilizer. Nitrate is a form of nitrogen that is found in inorganic fertilizers.

When fertilizer is needed and applied correctly, the lawn absorbs the nitrogen. However, fertilizers applied improperly can run off lawns and into local water bodies, harming water quality and threatening the plants and animals that depend on clean water for survival.

Watering-in your fertilizer after application requires no more than ¼ inch of water. To determine how much this is, perform a catch-can test. Place empty cat food or tuna cans around the perimeter of your irrigation system and time how long it takes to fill them to ¼ inch.

Do this before fertilizing so that you know how long to run the system. This will put the nutrients at root level, where they can be taken up most efficiently. Watering-in with more than ¼ inch of water can result in fertilizer leaching more rapidly through the soil.

The South Florida Water Management District has created a series of tools to help residents learn to use fertilizer appropriately.

By visiting www.WaterMatters.org/fertilizing, residents can get step-by-step instructions on fertilizing appropriately as well as watch a series of corresponding how-to videos.

Residents can also order the free 20-page, “Do-It-Yourself Guide to Florida-Friendly Fertilizing” for additional information.

Fertilizing appropriately is one of the nine principles of Florida-Friendly Landscaping™, a set of guidelines developed by the University of Florida’s Institute of Food and Agricultural Sciences to protect our natural resources while promoting beautiful landscapes.