The season has wrapped up here in the Northeast, and many golf courses have long since been put to bed for the winter. It seems each year there is something new to be concerned about, from preventing unusual ice damage and snow mold control to the best late season fertilization program and water quality.
Some superintendents believe that getting the course prepped for winter is becoming more complicated as we strive to maximize the revenue from golf into fall. Yet, if you pay attention to smart business professionals such as Jim Koppenhaver at Pellucid Corp., you’ll see that golfers are more like bears than squirrels (i.e. better spring weather drives more rounds than does a longer fall season).
If you are like me and trust Pellucid’s data (available to members at www.pellucidcorp.com) then it makes sense to sacrifice some performance this fall for better turf and playing conditions in the spring. This might include backing off the mowing and rolling, doing some tree removal to increase fall light levels, and installing slit trenches or bore holes in the surface to allow for drainage in bowled areas.
Turf loss from direct winter damage, not disease or traffic, is becoming more frequent and affecting a larger area. For example, a significant amount of putting green turf was killed this year from freezing and thawing weather patterns in the Northeast. Often, this is referred to as crown hydration. The causal weather patterns occur in the transition from winter to spring and are occurring with alarmingly regularity.
Winter survival is about managing water. Specifically, the ability for the putting surfaces to shed the water and prevent accumulation of precipitation that leads to ice development….
Winter survival is about managing water. Specifically, the ability for the putting surfaces to shed the water and prevent accumulation of precipitation that leads to ice development. Some superintendents constantly remove any snow that lands on the surface others apply protective covers that prevent snow from adhering directly to the surface. Many do both.
It is time to plan now, even if you have never lost turf to ice damage and the subsequent crown hydration. Research at Iowa State University by Dave Minner, Ph.D., showed that annual bluegrass was significantly damaged when encased in ice for 14 to 17 days. The same study showed creeping bentgrass could sustain ice cover for as much as 30 days before significant damage occurred. But this is only part of the story, especially for annual bluegrass.
The more important issue is the breaking of dormancy that occurs in late winter or early spring when the plants are submerged in water from melting snow and ice. The water warms on a sunny day, even with air temps in the teens and 20s. Annual bluegrass breaks dormancy, begins to grow, temps drop, the water freezes, the plant is hydrated and the crown of the plant is killed.
The breaking of dormancy has been shown in research to occur rather rapidly. Work from both the Prairie Turfgrass Research Center in Saskatchewan and currently under way at the University of Massachusetts by Michelle DeCosta, Ph.D., shows that warming of 12 to 24 hours of temps in the 40s can reduce winter hardiness of annual bluegrass almost by 400 percent. This is why when the plants die after they sit in water, warm up and grow and then freeze again.
Old, bowl-shaped greens that accumulate water are especially vulnerable to this type of damage. If you cannot reshape/rebuild then you should install temporary drains or bore a hole in the low spot that is deep enough to shed the water. Another option is to apply an impermeable cover, preferably something like the bubble solar pool covers. These should be dug into the collars to prevent water from seeping underneath. Of course you must have snow mold protection down since you are creating an ideal environment for disease.
There is some risk from the impermeable covers because they suffocate the surface in their own way but often retain enough air under the bubbles to prevent such damage. There is research being conducted in Quebec that found low oxygen levels usually are the issue, not the buildup of toxic gases. However, researchers found greater damage to putting surfaces with higher organic matter.
As competition for golfers heightens, courses that can provide reliable spring conditions will have an advantage. This is a message many clubs must embrace and one that superintendents should use in their discussion of resources needed to reduce winter damage.
As competition for golfers heightens, courses that can provide reliable spring conditions will have an advantage. This is a message many clubs must embrace…
The long-term solution is to reduce the amount of annual bluegrass in your surfaces that is more vulnerable to winter damage. This might not be realistic for many clubs due to the disruption of regressing, the chemical applications required, growing environment alteration, etc. That leaves many with only short-term options.
Focus your attention at this time of year on minimizing the accumulation of winter precipitation on your putting surfaces. Consider investing in covers for perpetually weak greens, budget time and resources for temporary drain installations, and work to improve light penetration to these greens in the fall. This will allow you to finish strong and be ready for the squirrels in the spring.
(Originally published in TurfNet Monthly, Nov/Dec 2011)
Frank S. Rossi, Ph.D., is associate professor of turfgrass science at Cornell University in Ithaca, N.Y. He can be reached at firstname.lastname@example.org.