Winter On The Course - Freeze Injury

FREEZE INJURY

If you watched the video on Freeze Smothering I linked to yesterday, you may have heard Dr. Karl Danneberger mention that ice formation, although able to sufficate turfgrass, is most often associated with freeze injury.  Freeze injury occurs when water in the plant freezes and results in death.  Freeze injury most often occurs in the early winter time or early spring when temperatures can be very warm during the day, then drop below freezing at night.

The turf's natural defense against freeze injury is its ability to harden off for the colder months.  The plant does this by moving water from inside cells to the outside.  This increases the concentration of solutes inside the cell to help prevent its vulnerability to freezing.  When the plant begins to loose the green color in the late fall, this process is underway.  When the plant does not have the time to complete this process, it is exposed to possible freeze injury.  As an example, this could happen when rain falls during the day and the plant takes up the water from the rain, but, after the rain pushes through, the temperature drops rapidly to below freezing and freezes the water the plant just took up.  As you know, when water freezes it expands, this leads to ruptured cell membranes which results in the death of the plant.

Freeze injury is nearly impossible to prevent due to its reliance on weather conditions.  Things that can help avoid the possibility of freeze injury are adequate sunlight and good surface and subsurface drainage; but those things should be done already to provide good turf.