Winter wheat survival is based on the environment, the variety, size and vigor the plants and the time of year/state of hardening. 

Fall cold snaps down to –15°F can generally be tolerated if seeding has reasonable development.

Table 1. Maximum number of days winter wheat can survive at different soil temperatures.

The temperature at crown depth is critical for winter wheat survival.   University of Saskatchewan research shows that cold hardiness changes through the winter and spring (See Figure 1).  If crown temperatures remain –4°F or above during winter months, successful overwintering is expected.  Three inches of snow is usually sufficient to keep crown temperatures in this range (see Table 2).

Plant hardiness varies across winter wheat varieties. Generally, winter wheat varieties from Canada or North Dakota will be more winter hardy then varieties from South Dakota or Nebraska.  

Winter hardiness is reduced as spring approaches.  Alternate freezing and thawing can hurt plant hardiness and survival, especially if winter wheat breaks dormancy for a few days during a warm-up of above-freezing night temperatures followed by night temperatures returning to below freezing.

A bag survival test can be to alleviate worry.  Retrieve winter wheat seedlings from a field. Clip roots below the crown and stems one inch above the crown. Rinse the crown in cold water and place in plastic zipper bag puffed out with air. Repeat rinsing and adding air every 2 days.  Plants that are not growing after 6 days should be considered dead. 

From: The Small Grains Field Guide A-290, J.J. Wiersma and J.K. Ransom, 2005.  Winter Wheat Production Manual. Crop Development Centre, University of Saskatchewan, Saskatoon, Canada. Winter Wheat Management, J.K. Ransom et al., webinar, 2013.