Florida Winterizer Fertilization

Florida Winterizer Fertilization of warm-season grasses if done should be done with a nitrogen-free product and applied prior to dormancy. Although many brands promote the sale of Winterizing fertilizers that include nitrogen, these are not appropriate for warm-season grasses. They encourage new grass blade development that alters the dormancy cycle that, by design, is nature’s way of protecting the plant from cold damage—waking the plant before a freeze puts it at risk of increased stress and death. “Many of the so-called winterizer fertilizers available in our area can cause more damage than good,” according to UF/IFAS. “The time to fertilize our warm-season grasses in Florida is during the growing season, not when the grasses are going to “sleep” for the winter.”

The three macro-nutrients listed on the label of all fertilizers are nitrogen, phosphorus, and potassium, abbreviated as NPK. If choosing a Wintering lawn fertilizer, we only recommend an NPK with phosphorus and potassium. “Adding phosphorus to soil low in available phosphorus promotes root growth and winter hardiness, stimulates tillering, and often hastens maturity,” according to University of Nebraska Plant & Soil elibrary. “Potassium is a vital component of numerous plant functions, including nutrient absorption, respiration, transpiration, and enzyme activity.” Both phosphurus and potassium are essential for plant maintenance and support, according to the Noble Research Institute.

Our Florida Winterizer Fertilization recommendation is for an NPK of only phosphorus and potassium. This nitrogen-free formulation is most readily available for retail sale with a 0-10-10 NPK.

It’s also essential to know your soil pH when supplementing with fertilizers. These macro-nutrients are only fully bioavailable at a pH of 6.5 or above and decreasingly available below. “In a very acid soil of pH 5.0 only 40% of the nitrogen is available, 35% of the phosphorus and 50% of the potassium,” according to Allotment Garden.org. “Increasing to an average plot’s pH 5.5 takes the nitrogen and potassium up to 70% availability but the phosphorus is still only at 45% availability. It’s not until the pH hits 6.5 that all the big 3 nutrients are fully available to fuel the plants.”

Where can I get my soil analyzed?
The University of Florida Extension Office in Duval County provides free soil pH analysis that takes typically 7-10 business days to get results. Samples should be dry which is best provided to them in paper bag whereas plastic holds moisture. Samples should be gathered from a few different areas of the landscape and dropped off in person at the extension office.
Contact the University of Florida Extension Office in Duval County for more information at (904)255-7450. Find out more about soil and soil testing in our article Soil Testing In Northeast Florida.

For comprehensive solutions to your specific lawn, garden and landscaping need contact Earth Works of Jacksonville online and at 904-996-0712. Earth Works operates a retail Garden Center/Plant Nursery in Jacksonville and provides landscaping, hardscaping, water features, lawn care service, lawn spraying, and drainage solutions.

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