There has been no shortage of snow cover at most courses across the Upper Midwest. Several early storms followed by a blizzard produced a deep layer of insulation across the region’s golf courses. Generally, a dense blanket of snow is the ideal scenario to ensure turf survival by protecting the turfgrass crowns from frigid temperatures.
However, the current snow cover may be a two-edged sword this winter. Several days of unusually mild weather accompanied by rain, just prior to the first of the year, melted nearly all of the December snow except for playing surfaces located in low-lying, protected sites that tend to accumulate extra deep snow cover. Exposed sites that lost all snow and frost in the ground benefited from the current snow cover, but protected sites found the frost impeded water movement through the turf and were sealed beneath a dense layer of solid ice to start the year. Snow cover over the ice-affected turf increase the potential for ice suffocation.
Several superintendents have sampled turf under the 30 to 40-day old ice cover and the stench of anaerobic conditions (lack of oxygen) beneath the ice was overwhelming. The smell of decaying turf and organic matter is never a good omen, but plugs of turf taken indoors to green up did not appear to be injured.
A week of mild temperatures has many superintendents weighing the pros and cons of removing snow from greens to expose ice to sunlight and warm temperatures. There is always risk and reward involved when attempts are made to remove ice, but the risk of allowing ice to remain any longer on greens that already have an anaerobic smell is probably greater than the potential for causing damage by removing snow.
If the greens are not affected by ice, the best bet is to let nature take its course with respect to snow cover. Perhaps clearing a path or channel along the perimeter of the green to allow the water from melting snow to flow off the putting surface is worth the effort, but keep the plows, snow blowers, and shovels off the greens.
On the other hand, it makes sense to remove snow from greens that already have six-plus weeks of uninterrupted ice cover and then apply some type of darkening agent to the surface to at least honeycomb the ice and vent the anaerobic gas accumulations. Black sand or dark-colored organic fertilizer products, such as Milorganite, are commonly used to speed up the process of ice removal.
As always, the key to making the best decision is to monitor turf conditions beneath the ice and snow as often as possible throughout the winter and pay special attention to sites that have a history of winterkill.
Source: Bob Vavrek, rvavrek@usga.org or 262-797-8743