There are many different situations that can lead to winter injury of turfgrass. Possible causes include plant dehydration or desiccation, crown hydration damage, ice sheet formation limiting gas exchange, and freeze/thaw cycles. As weather changes every year, it’s always possible to incur winter injury on some part of the golf course due to one of these scenarios.
Two situations in particular stick out this year with the recent weather and those are freeze/thaw cycles that may lead to crown hydration injury and ice sheet formation. Normally, freezing and thawing cycles can be beneficial by fracturing apart tight soil and sand particles thereby creating new space for oxygen and water movement. On the other hand, very quick freeze/thaw cycles can result in turf loss due to crown hydration injury or ice sheet formation that does not allow gas exchange.
Three days ago the turf was covered with about two inches of snow, but that quickly changed as it melted away during the warm temperatures followed by a fair amount of rain. While the ground was still frozen roughly 5-6 inches below the turf surface, there wasn’t a lot of room for the water to go other than stay on the surface.
Our staff saw the forecast coming and acted quickly in removing as much water as possible from greens to avoid turf damage.
Temperatures quickly dropped below freezing again last night which has led to ice sheet formation in multiple areas where there was standing water. This situation has the potential to lead to turf loss, especially in areas covered by annual bluegrass or “Poa annua”. Annual bluegrass, the predominant turf species of putting greens in northern climates of the United States, has a higher susceptibility to winter injury than creeping bentgrass.
With that said, there are many times when annual bluegrass has survived during harsh conditions so only time will tell whether or not mother nature has been nice to everyone this year!