By BJ Jarvis
UF/Pasco Extension Director
As weather starts to feel more like spring, many Floridians are thinking about spreading some fertilizer.
When we are talking about fertilizers, it is mainly for turf because trees and shrubs usually don’t need fertilizing once well established. Generally, lawns need fertilizers no more than twice per year. The first application can be anytime in March or early April, with a second dosage in the fall.
Nitrogen, the first number on the bag, is the main nutrient turf typically needs for encouraging green leafy growth. To provide plant nourishment for an extended period of time, choose supplements that are at least half of the nitrogen in a slowly available form.
Slow release, timed release or controlled-release are all the same way of saying the formulation saves money and can produce a healthier, more weed-free turf by supplying small amounts during a longer period of time.
Choose a brand that skips the phosphorus, the middle number on the fertilizer bag. Florida soils are naturally rich in this element, so why buy more? The middle number should be zero or no higher than a 2.
Never fertilize right before it rains. Precious and expensive fertilizers will leak down through the soil or run off rather than remain in the root zone. It can then become a pollutant in waterways or the aquifer, our main source of drinking water.
If your property is adjacent to a waterway or retention pond, maintain a 10-foot maintenance-free zone, including for fertilizers.
Turf that is “pushed” with lots of inputs like fertilizer, but also includes water and other chemicals, tends to fail. In addition, repeated applications of nitrogen tend to increase pests and stresses plants. Therefore, more is not better.
A healthy lawn does not need to be pushed with fertilizers during the entire growing season. Cultivating a lush, pest-resistant and weed-resistant lawn can also be less expensive by only applying fertilizers twice per year.
—BJ Jarvis is Director and Horticulturist for Pasco Cooperative Extension, a partnership between the University of Florida, USDA and county government. She can be reached at or by phone at (352) 518-0474.