December Turf Tips - Homeowners

Jeffrey Derr and Adam Nichols

Winter Turf Tips for Homeowners

Although temperatures have gotten cold, warm-season turf species are/or are going dormant, and tall fescue has slowed down its growth, there are still things to consider turf-wise this winter. Now is a good time to do a soil test. If your soil has become too acidic (pH below 6.5), one can add lime this time of year. A soil test will also give the current status of phosphorus and potassium in the soil, which will determine fertilizer needs in 2026. Now is not the time to fertilize warm-season grasses (bermudagrass, zoysia, St. Augustine, centipede). One can apply fertilizer to tall fescue in December if needed amounts were not applied in the fall but lower rates are recommended due to its slower growth during this time of year. Fertilizer applications made during the winter need to be made with a nitrogen source that does not require microbial breakdown to make the nitrogen available to plants. Suitable fertilizer products for winter applications to tall fescue are sources containing ammonium or nitrate nitrogen or isobutyidene diurea (IBDU).

Now is a good time to apply postemergence broadleaf herbicides for control of winter weeds like common chickweed, henbit, lawn burweed, speedwells, and vetch. It is better to treat these weeds when small compared to spring when these weeds are much larger and thus harder to control. Treat under warm conditions (over 50 F), good soil moisture, and light winds. In tall fescue, consider a triclopyr-based product or a 3-way or 4-way product containing dicamba. Ester formulations are preferred as they are absorbed through the waxy coating on leaves better than amine forms, especially during cold weather. An example of an ester formulation of triclopyr would be Monterey Turflon Ester, while an example of an amine form of that herbicide would be Ortho® Weed B Gon Chickweed, Clover & Oxalis Killer for Lawns. Bioadvanced Lawn Weed Kiler would be an example of an amine form of a 3 ingredient herbicide (3 way), while Gordon’s Speed Zone would be an example of a 4-way product that contains ester 2,4-D. Amine forms are preferred for summer applications.

Esters pose less risk of off-site plant damage in winter compared to summer as deciduous trees and shrubs have dropped their leaves and thus are less likely to be injured by drift. Make sure that these broadleaf herbicides do not drift onto pansy, winter vegetables, and evergreen ornamentals, though. The 3-way and 4-way broadleaf herbicides can also be used in bermudagrass and zoysia. Hi-Yield Atrazine is an option for postemergence broadleaf and annual bluegrass control in St. Augustine.

Emerged annual bluegrass will be a challenge for homeowners as there are no easy answers in tall fescue. In bermudagrass and zoysia, there are a number of selective options for annual bluegrass control but sample sizes make them more appropriate for commercial applicators. A special option in bermudagrass is dormant applications of glyphosate. This is probably best used in the month of January when bermudagrass is completely brown. Watering one week after application will lessen the potential for any turf injury. Later applications, when bermudagrass is starting to green up, pose a risk of injury.

One can get an early start on preemergence crabgrass control by applying a product such as prodiamine (Barricade, others) during the winter as cold weather limits breakdown by microorganisms. One generally will not see season-long control, as a second application will be needed in in late spring. Applying a crabgrass preventer / fertilizer combination to tall fescue during the winter is not advised as the fertilizer rate may be too high when applying the recommended rate of the crabgrass preventer plus the timing is not right for the fertilizer. Another advantage of s crabgrass preventer application in winter is that it will control Japanese stiltgrass (Microstegium), which germinates earlier than crabgrass, sometimes in late February if warmer conditions occur.

During winter storms, i.e. snow and ice, fertilizers are not to be used as ice melt. Also, when using ice melts, take caution to keep it onto hard surfaces, and any snow or ice moved off of hardscapes treated with ice melts can have dissolved salts that can cause damage if left on the turf and allowed to melt. Finally, limit traffic over frost-covered tall fescue or other cool-season grasses to prevent injury to the leaf blades.