No fertilizer containing nitrogen or phosphorous should be applied to lawns from June 1-September 30 of each year. Here in the Tampa Bay region we can get heavy rainfall virtually any day during these months, increasing the chance that fertilizer granules will be washed down the storm drain and into the nearest waterway.
Nitrogen is a key component of fertilizer, and is the major pollutant in the Tampa Bay watershed. Too much nitrogen causes algae blooms that turn our lakes, ponds and bays into a pea green soup and deplete oxygen needed for fish.
Instead of using nitrogen on your lawn in the summer, use a slow-release nitrogen fertilizer in the Spring, when the grass is beginning to grow. Buy a slow-release product that releases the nutrients over a period of several months, and your yard should remain healthy through the summer.
If you want to "green up" your yard in the summer, use iron, potassium or other micro-nutrients. Several companies already are selling such nitrogen-free fertilizers, including:
NOTE: Phosphorous is not usually needed in the Tampa Bay region because our area has an abundance of natural phosphorous.
Don't apply fertilizer containing phosphorous at any time without conducting a soil test to determine if you need it. Your local extension
office can tell you where and how to submit a soil test for just a few dollars.