Low temperature tolerance of zoysiagrasses

Abstract

Rhizomes of zoysiagrass (Zoysia spp.) were subjected to controlled freezing tests in Jan. and Mar. 1993 and 1994 to determine their low-temperature tolerance. In 1994, 'Belair', 'Korean Common', 'Meyer', and 'TGS-W10' rhizomes survived temperatures as low as -18 °C, while rhizomes of 'Sunburst' survived -14 °C. 'Cavalier', 'Crowne', 'Palisades', 'Emerald', and 'El Toro' were killed at -10 °C or warmer temperatures. Entries surviving exposure to-14 to-18 °C in 1994 controlled freezing tests received postwinter survival ratings in the field of 6.7 to 8.7 (9 = 100% green). Entries killed at higher freezing test temperatures were slower to recover after winter in the field, with ratings of 2.0 to 3.0. Shoot number produced after freezing was a better measurement for assessing low temperature tolerance than was shoot mass. Controlled freezing tests, using regrowth as a measure of hardiness, appear to be useful for identifying low temperature tolerance of zoysiagrasses in the early years of a field study.