With the relative mild weather and rain through most of the Eastern and Upper MidWest this week, freeze tolerance of turfgrasses probably not in the forefront of the thought process.  However, winter will come soon enough.  Freeze tolerance is the temperature needed to kill a turfgrass plant when it is most cold hardy.  At the moment turfgrass plants are probably as freeze tolerant as they can get.  Most injury occurs when turfgrasses break their dormancy or hardiness.  Additionally, snow cover provides protection or an avoidance mechanism to the direct cold.  The following turfgrasses are ranked according to their freeze tolerance with the relative killing temperature in Fahrenheit.

Turfgrass                               Relative  Killing
                                           Temperature (F)
Creeping bentgrass                 -4 to –31
Kentucky bluegrass                -4 to –22
Red fescue                                      -6
Perennial ryegrass                    5 to –4
Tall fescue                                      14
Bermudagrass                                19
Seashore paspalum                        19
Centipedegrass                       12 to 21
St. Augustinegrass                         23
Carpetgrass                                   23