Superintendents at a number of courses in the North-Central region have documented at least 60 to 70 days of ice cover beneath a deep layer of snow across localized areas of putting greens. Research indicates injury to Poa annua is likely to occur under these conditions. Consequently, the maintenance staff at many facilities that have predominantly Poa annua greens could not resist the urge to remove snow and ice during a recent brief period of mild weather.
However, the temperatures plunged to 25 to 30 degrees below normal after the short-lived thaw and northern states have remained in the deep freeze for a week and counting. Poa annua exposed to single-digit temperatures during late winter without insulation from snow cover may be just as likely to experience injury as the turf suffocated by months of ice cover.
The bottom line is that Mother Nature seems intent on making life miserable for turf this winter regardless of what measures are taken to prevent injury. The aroma of rotting grass when ice is removed is never a good sign and reports of putrid smells from putting greens have increased lately. Similarly, plugs of turf removed from frozen greens earlier this winter appeared healthy when moved indoors, but only the bentgrass component of the turf seems healthy and vigorous in recent samples. Only time will tell if affected areas of greens are truly dead or only mildly stunted by the double whammy of winter stress. We won’t know the scope or magnitude of turf injury until a sustained period of mild weather occurs.
Fortunately, we have more control over the factors that facilitate turf recovery versus the factors that cause winterkill. The Green Section staff will be providing recipes for recovery should significant turf loss occur. Until then, let’s hope for the best and prepare for the worst.
Source: Bob Vavrek ( rvavrek@usga.org)
Information on the USGA’s Course Consulting Service
Contact the Green Section Staff