Ice Formation and the Potential for Winter Damage

Thirty-nine inches of snow have fallen in the Detroit area so far this season which is double the normal amount.  While this makes tree removals and pruning difficult, it doesn't pose that much of a threat from an agronomic standpoint.  Of real concern is the 1" of rain Northville received two weeks ago.  When this precipitation reached the ground after working through the snow layer and temperatures dropped below freezing (which occurred two days after the rain) ice was observed on the surface of the greens. 
This type of weather can lead to winter damage on greens, usually in two different ways (specific to MCC, winter damage in general can occur in a variety of ways).  The first of these poses a very serious threat because of our grass type.  Poa annua can and will break dormancy at the first sign of higher temperatures.  Breaking dormancy mid-winter is dangerous, plants will uptake water and when the inevitable freeze occurs, this moisture will freeze within the plant, forming ice crystals that will puncture cell walls and membranes and result in plant death.  Readers might be familiar with this process already, known as crown hydration.
The other way winter damage is suspected to occur at MCC is by ice build-up on the green surface.  If ice forms thick and dense enough it can create an impermeable layer to gases.  Turf can than be susceptible to anoxia (unlikely, dormant plants need minimal oxygen) or the accumulation of toxic gases given off by cold weather fungi and bacteria. 



Ice on the 17th green appears to be porous, hopefully allowing for air movement

Thicker ice forming on the 15th green

 

Minimal ice formation on the practice putting green

 

 

Winter damage, and the ways it occurs, is problematic to research.  Particularly in Michigan where cold season weather can vary so much.  Poa annua can survive under dense ice cover but not indefinitely (approximately 60 days according to Dr. James Beard of Michigan State University, 1964).  In comparison, creeping bentgrass can survive much longer under these same conditions.  We appreciate any winter sport enjoying members to please not cross greens or tees when at MCC and all members to keep their fingers crossed for minimal winter damage when the snow clears.  Stay warm and enjoy.