This article originally ran in the Ruston Daily Leader on October 30, 2012.
I’ve received several phone calls in recent weeks from clients asking about the need and importance of winterizing their lawns. It’s true; lawn winterizing products have been on the shelves of lawn care centers for a month or more now. For warm-season lawns, the term “winterize” is simply stated as slowing down plant growth and increasing plant levels of the nutrient potassium (K). Research has shown that higher levels of potassium in the plant can enhance cold tolerance, thus reducing the damage incurred by winter frosts.
It is important to understand that many of the products marketed with “Winterizer” on the fertilizer bag are formulated for cool-season grasses in the northern states. The “northern” formulations contain a high percentage of nitrogen, much higher than what our “southern” grasses need. The high level of nitrogen present in the fertilizer promotes shoot growth at about the same time the plant is slowing down its growth going into fall and winter.
Consumers in Louisiana should be looking for a southern type winterizer for their warm-season grasses to avoid the plant-softening effect of using a northern, high-N formulation. Southern winterizer formulations have a low nitrogen content, little to no phosphorous (P), and a higher K content.
If soil test results indicate a necessary increase in potassium levels, murate of potash (0-0-60) is an option. Remember, there is no advantage to applying excessive amounts of potassium. In fact, applying excessively high rates of potassium can cause foliar burn and may compete with other nutrients (especially magnesium) for uptake into the plant.
The best strategy is to maintain adequate to optimum nutrition levels throughout the growing season. And, the only way to know the specific needs of your lawn is to have a soil analysis completed. Soil test boxes and forms are available from the local LSU AgCenter office.
Soil test results will indicate current levels of soil nutrients and what is needed to bring levels to optimum conditions. If adequate levels of N, P and K are available all season, the turf is in the best shape to handle environmental and pest problems all season long and special winterizing is unnecessary. However, using any fertilizer blend can be more harmful than beneficial if incorrectly applied. If you have any questions about lawn care, feel free to call me or your local LSU AgCenter agent for more information.
The LSU AgCenter and the LSU College of Agriculture