Cover Story
Prepping Lawns for Winter By Jeff Wilson, Ph.D., Jay McCurdy, Ph.D., and Barry Stewart, Ph.D., Mississippi State University
It’s
usually around this time of year that homeowners start losing interest in their lawns. Temperatures are pleasant, the days are getting shorter, and the droning of lawn mowers is replaced by the sounds of televised football (and leaf blowers). Most of us are just happy that turf growth is slowing down and that we don’t have to mow the grass every week. Our staff is happier. We’ve made it through another busy summer. As the days become shorter, though, our grasses tend to become a bit leggy, and holes may develop in our turfgrass culture. Now is the time to sharpen up and focus on fall agronomic practices that are important for next year’s season. What we do now has a big impact on what happens during the winter and even next spring. The most glaring shortcomings of any lawn-maintenance regime are these: proper fall fertility and fall weed control. The two most imporTable
tant things you can do to keep your turf healthy are to apply the proper amount and type of fertilizer and to properly apply the right pre-emergence herbicide.
Fall fertility
Before we do anything, it’s a good idea to know two things. The first thing to know is the lawn’s turf species. Not all products can be used on all species, and of course, some grasses need a bit more fertility than others. For instance, centipedegrass requires very little supplemental nitrogen, and bermudagrass needs, well, a lot (Table 1). Many homeowners and lawn care operators overlook turf type. Because of this, they are constantly battling bermuda in their centipede or, vice versa, centipede and bahiagrass in their bermuda, not to mention clovers and other legumes. Whatever the desired species, it is up to us to manip-
Turfgrass nitrogen requirements vary depending upon species and environment. These are just guidelines. Older, more mature lawns may need far less in order to maintain good color and turf density.
1
Turf Type
Lbs. N / 1,000 ft2 / year
Application Timing
Centipedegrass
1 to 1.5
May
Bahia
3 to 4
May, June, August
St. Augustine
3 to 4
May, June, Aug./Sept.
Zoysiagrass
3 to 4
May, June, Aug./Sept.
Bermudagrass
5 to 6
May, June, July, Aug., Sept.
Tall Fescue
4 to 5
Sept., Oct., March, April
10 • Mississippi Turfgrass • Fall 2014
ulate agronomic practices to favor that species. If you are unsure of what turf you have, simply cut out a section that is 6" x 6" and take it to your local MSU Extension office to be identified, or send us a close-up photo that’s in focus. The second piece of information we need at this time of year are the results of a recent soil test. To optimize turfgrass growth, we need to routinely (once every two to three years) perform a soil test. Information on how to take a soil test is available at http://msucares. com/pubs/infosheets/is1294.pdf. Your county Extension office has a supply of soil-testing boxes and forms, as well a soil probe that can be borrowed (if needed). A standard soil-test report will include pH, which will dictate liming practices. Soil pH and the consequent lime recommendation are very important pieces of information because soil pH affects nutrient availability. If lime is required to raise soil pH, fall is an excellent time to apply it. Winter’s timely rainfall helps integrate lime into the soil profile, and fall’s slower schedule makes liming more feasible. The soil-test report will also include a recommended nitrogen application according to turf species and recommended supplemental nutrient applications based upon soil concentrations of phosphorus, potassium and calcium. Most (probably all) of the “winterizer” fertilizers are developed for the cool-season grass market.