As I took a break from shoveling eight inches of snow from my driveway, it occurred to me that this is a good time to discuss ice accumulation and its potential to cause damage to turfgrass. The forecasted 1 to 1.5 inches of snow quickly turned into, surprise, 6 to 8 inches across most of the greater Philadelphia area and lesser amounts in other parts of the region. At the time of writing, another storm is already in progress and expected to deliver another 6 to 8 inches. Do not find yourself surprised and unprepared like I was. Have plans in place to remove water and ice from low-lying areas to prevent winter injury to fine-turf playing areas.
For golf facilities with a relatively high population of Poa annua and/or perennial ryegrass, ice accumulation presents a serious concern. As snow melts, water will run to low-lying areas, much the same as heavy rainfall. Unlike summer when water has the ability to percolate downward through the soil, soils are frozen during winter. The result is extended periods of standing water. If allowed to stand for too long, standing water may turn to ice leading to winter injury of turf. Additionally, anaerobic soil conditions can develop beneath ice coverage leading to increased risk of plant injury or death.
Generally, creeping bentgrass and Kentucky bluegrass possess excellent cold tolerance and even tolerate ice encasement for long periods of time. Conversely, Poa annua and perennial ryegrass are much less tolerant to both cold temperature and ice encasement. Poaannua can generally survive beneath ice cover for 30 days or less whereas bentgrass can survive under ice for 60 days or more. Not surprisingly, those with Poa annua putting greens get especially nervous during long periods of snow and ice cover.
The best way to prevent ice from accumulating on the surface of your important playing areas is to install adequate subsurface drainage with multiple inlets along prominent drainage channels. This type of drainage is equally beneficial in summer following heavy rain events. Before winter arrives, it is important to clear leaves and other debris from subsurface drainage inlets. Additionally, trim around each drainage cap to ensure large volumes of water can freely move into the drain. A helpful tip to ensure you can always find your drain basins is to place an irrigation flag next to each entry so it is easily located even under heavy snow. Do not wait until after it snows to decide that you need to address this problem.
Following thaw cycles, inspect your course for pockets of water on fine-turf areas. If additional freezing weather is forecasted, use a squeegee or similar tool to direct surface water to the nearest surface drain before it turns to ice again. Continue this process until all free water has been removed from important play areas to reduce the likelihood of damage occurring.
For those who have waited to apply snow mold protection, take advantage of your first available opportunity. Time is running short and you do not want to go into winter with fine-turf areas unprotected. Timing is everything when it comes to snow mold applications. If applied too late, freezing temperatures or frozen ground can prevent the fungicide from being completely effective, if able to apply at all. In most of the mid-Atlantic region, mowing is finished for the year, but if weather conditions change and you are forced to mow due to turf growth, additional snow mold treatments are recommended.
If your golf facility elects not to apply snow mold protection to fairways, be prepared for potential damage come spring. Remember, pink snow mold (Michrodochium nivale) can occur without the presence of snow. There is always a delicate balance between the cost of treating fairways for snow mold prevention or not. Be prepared to communicate with golfers and course officials in the event that snow mold damage occurs.
Finally, as a friendly reminder, we hope to see you at either of the two USGA Green Section Mid-Atlantic regional meetings scheduled for March 2014. Specific dates and locations are as follows:
March 4, 2014 at DuPont Country Club in Wilmington, Del.
March 11, 2014 at Oakmont Country Club in Oakmont, Pa.
Source: Elliott L. Dowling (edowling@usga.org)
Information on the USGA’s Turf Advisory Service
Contact the Green Section Staff