2015 Winter Damage of Warm-Season Grasses
Through the first two weeks of February 2015 it seemed we were going to have a mild winter. But then the teens and single digit temperatures hit. It is times like this that golf courses really need to pull covers over their bermudagrass greens. While covers do not totally prevent winter damage, they have prevented freeze damage in areas that are normally far colder than eastern NC. In these colder areas, superintendents often add a layer of straw under the cover and/or double cover for added protection.
One difference this winter is that in many areas, cold temperatures (low single digits) occurred with no snow cover. During the winter of 2014, the coldest temperatures occurred when snow cover was abundant, particularly in eastern NC. This lack of snow cover increases the probability of winter injury. However, it is still too early to determine if/how much winter injury has occurred. In addition, there is still quite a bit of winter left.
As for non-golf course areas, it is tough to know how damaging the cold temperatures have been. A good test is to pull plug(s) from the turf and put them in a cup and set inside in front of a southern exposed window [if you have an actual greenhouse, that is even better]. Within about a week, non-damaged turfgrass will begin to put out shoots.
Last year, fine-textured zoysiagrass and centipedegrasses had the greatest damage. Freeze damage may be sporadic and actual damage can be very difficult to predict. North facing turf and saturated soils are usually more prone to damage. Any secondary stresses make freeze damage more likely. Weak turf going into the winter is more susceptible to winter damage than healthy turf.
Generally herbicide applications do not cause increased winter damage. But some pre-emergence herbicides can make re-establishment of turfgrasses more challenging. Most product labels have information related to re-establishment timings following application. Establishment timing following herbicide applications may also be herbicide rate-specific.