With the long winters we have in Canada, the amount of snowfall and the ups and downs in temperature, winterkill is one of the most stressful things come spring for golf course superintendents. There are a few things that cause winter damage; these include Desiccation, Freeze Injury / Crown Hydration and Anoxia.
Desiccation occurs when the water loss from the turf exceeds uptake and transport from the roots. Desiccation can only occur when there is no snow cover. Desiccation occurs from soil drought when their is minimal soil moisture and no precipitation. This occurs when the ground is frozen and the roots of the grass are unable to replace the water because it is frozen. Another thing that can cause winter damage is Freeze injury / Crown Hydration. This occurs when the temperature is extremely cold or there is a rapid drop in temperature. When this happens the water inside the plant’s cells freezes and damages the cell membranes causing the plant’s cells to die. The third thing that can cause winter damage is called Anoxia. Anoxia is a condition that can occur from snow and ice cover and even protective covers. It is a result of different gases that build up and get trapped under the snow and ice cover or protective covers. This causes there to be no gas exchange and the turf plant will evenly run out of the energy it needs to survive. Anoxia can usually be detected in the spring by the foul smell that will come from the green when you take the turf cover off. This is a result of the gases that have been building up and trapped all winter.
There are a few things you can do to prevent the causes of winterkill . To prevent Desiccation you can irrigate the turf prior to freezing, you can install snow fences to encourage snow build up on the greens and you can apply mulch or light topdressing on the greens before it gets cold out. A few things you can do to prevent freeze injury / Crown Hydration is fertilize late in the fall and increase the mowing height before winter. To prevent Anoxia, it is recommend that you put proper venting in your protective covers or not use covers at all. Overall, I feel that we can never really control the problems that cause winterkill but we can help prevent some of the damage from being as severe.
References/ Resources
Tough Turf Surviving Winter
GreenMaster, April 2007, By Pam Charbonneau
Preventing Winterkill
The Grass Roots, May 2008, By Dr. John Stier
