As we move into fall and winter, there are some things you can do to keep your lawn looking good.
First things first: Identify the type of grass you have in your lawn.
Next, read the appropriate University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) publication for your type of turfgrass.
For example, Central Florida has St. Augustinegrass (the most common lawn in Florida), bahiagrass, zoysiagrass and Bermudagrass.
One resource that can prove very helpful is a free online library at the University of Florida called EDIS, which stands for “Electronic Data Information Source.” (The EDIS website is http://edis.ifas.ufl.edu/).
After you know what type of turf you have, be sure to keep track of how much water your lawn gets by rain and irrigation. An inexpensive rain gauge is a good tool to measure rainfall.
During cool, winter months, many people skip a week of watering. Calibrate your sprinklers to make sure you deliver ½-inch to ¾-inch of water per irrigation event. If your sprinklers (or rainfall) provide that amount of water a few times per week, irrigation or rainfall is enough.
You’ll also need to check your fertilizer applications. Remember, Florida turfgrasses are warm-season grasses. They all go dormant during winter, which results in slower growth, and less needed inputs of water and fertilizer.
Lawns may turn brown or appear off-color, but resist the urge to fertilize your lawn in winter.
Winter fertilizer applications can damage lawns, especially zoysiagrass lawns, which have a very slow spring “green-up” period. Zoysiagrass prefers to be “spoon-fed” fertilizer. A winter fertilizer application on zoysiagrass can cause unhealthy turf the following year.
There’s a chart available through the University of Florida that provides general fertilizer recommendations for different turfgrasses. It also provides guidance on when to apply a complete fertilizer, slow-release fertilizer and other nutrients, if needed.
Look for the Central Florida section, then find your type of turfgrass.
The chart also provides recommendations for basic, moderate and high maintenance levels.
Turfgrasses which are under the “basic” or “moderate” schedule for Central Florida have no fertilizer applications during December, January and February, according to the chart.
It’s also important to keep in mind that many of our Florida soils are high in phosphorous (P) (we mine phosphorous locally). Therefore, you should not apply phosphorous unless you have a soil test report showing a P-deficiency. This happens occasionally, but since most of our soils have sufficient P, adding more in the form of fertilizer will not produce a crop or plant response because there is enough available. However, adding more P than needed can result in increased nutrient runoff and leaching, which affects our water bodies, groundwater and springs.
How do you avoid fertilizer that has P? When you shop, look for products with zero or very low phosphorous. These products are becoming increasingly available because of summer fertilizer ordinances and because people understand the potential for pollution if used when they’re not needed.
It’s also good to know that proper mowing height is one of the main things you can do to promote a healthy lawn.
Regular cultivars of St. Augustinegrass should be mowed at 3 inches to 4 inches; most dwarf cultivars of St. Augustinegrass should be mowed at 2.5 inches; bahiagrass should be mowed at 3 inches to 4 inches; zoysiagrass at 2 inches to 2.5 inches; and Bermudagrass at 0.5 inches to 1.5 inches.
In shady areas, consider replacing sod with an appropriate groundcover and mulch. Turfgrass needs at least six hours of sunlight daily, so if an area isn’t receiving that much, the lawn there will likely never thrive. A groundcover may be a better choice.
If weeds are an issue, find out if they are broadleaf, sedge or grassy weeds.
Make a note on your calendar and plan to use a preemergence herbicide around Feb. 15 in Central Florida to stop weed seeds from germinating and to reduce weed pressure next year.
A soil fertility test can tell you if your lawn is low in potassium. We’re learning a lot about potassium, including the fact that it contributes to healthy plants and turfgrass, and that it helps with disease resistance. When buying fertilizer, make sure the nitrogen (N) to potassium (K) is balanced with a 1:1 or 2:1 ratio.
Each fall, I over-seed my lawn with annual ryegrass. Ryegrass keeps weeds down during winter months and provides beautiful “Easter” grass color until it begins to warm up around April the following year. You can put ryegrass down in months that end in “R,” but I generally try to seed ryegrass in September/October to enjoy the bright, green color for months.
For additional information, contact or (813) 744-5519, ext. 54145.
Sources for this column included “Mowing Your Florida Lawn” by L.E. Trenholm, J.B. Unruh and J.L. Cisar; and, Weed Management Guide for Florida Lawns by J.B. Unruh, R.G. Leon, B.J. Brecke and L.E. Trenholm.
Nicole Pinson is the Urban Horticulture Agent in Hillsborough County.
Published December 5, 2018
