Little is known about environmental and physiological factors affecting centipedegrass [Eremochloa ophiruoides (Munro) Hackell winter survival. Stolons of common and ‘Oklawn’ centipedegrass were sampled from field‐ or growth chamber‐grown turf in three separate experiments to (i) determine freezing tolerance of acclimated and nonacclimated turf; (ii) identify and quantify nonstructural carbohydrates (NSC) in acclimated and nonacclimated turf, and (iii) relate levels to freezing tolerance. Lethal temperatures for common and Oklawn were similar throughout all studies. Freezing tolerance estimated by electrolyte leakage for turf sampled from the field in winter 1988–1989, indicated that lethal temperatures ranged from about −7 to −8 °C in February and March, to −9 °C in December and January. In a 1990–1991 field and growth chamber studies, injury was estimated by stolon recovery growth in the greenhouse after freezing at −2, −4, −6, −8, and −10 °C for 1 h. Lethal temperatures in mid‐winter were −2 °C lower than in fall or spring during active growth. In stolons, starch and sucrose were the primary NSC ranging from ≈2 to 13 mg (100 rag)−1 dry weight. Sucrose was higher in acclimated than pre‐ or post‐acclimated turf. In a growth chamber study, 47% more sucrose was present in acclimated vs. preacclimated turf. Sixty‐nine percent more acclimated stolons survived −4 °C than preacclimated stolons, and a positive correlation (r = 0.78) was observed between sucrose level and number of surviving stolons. Higher sucrose concentrations in low‐temperature‐acclimated vs. nonacclimated common centipedegrass stolons may be a component of improved freezing tolerance.

Little is known about intraspecific variability in St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] freezing tolerance and the physiological factors that may influence survival. Stolons of field-grown `Raleigh', `Floratam', and FX-332 St. Augustinegrass were sampled between October and March in 1990 to 1991 and 1991 to 1992 to measure freezing tolerance, nonstructural carbohydrates, and water content. Stolons were exposed to temperatures between 1 and -8C in a freezer, and regrowth was evaluated in the greenhouse. Generally, freezing tolerance of `Raleigh' > `Floratam' = FX-332. `Raleigh' exhibited >60% survival in December and January, while survival of `Floratam' and FX-332 was <20%. `Raleigh' was the only cultivar that acclimated, as indicated by a 75% increase in survival between October and December 1990. Starch and sucrose were the primary storage carbohydrates extracted from stolons, but neither was correlated with freezing tolerance. A negative (r = -0.80) correlation was observed between `Raleigh' survival and stolon water content between January and March 1991. Reduced water content in `Raleigh' stolons during winter months may contribute to acclimation.

Stolons of `Raleigh', `Floratam', and FX-332 St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] were sampled from the field between October and March in two consecutive years to evaluate accuracy of an electrolyte leakage (EL) method for predicting freezing tolerance. Lethal temperatures of stolons estimated using EL were compared to those obtained by regrowth tests in the greenhouse. Mean lethal low temperatures for regrowth and EL methods over 12 sampling dates were `Floratam', –4.5C (regrowth) vs. –4.4C (EL); FX-332, –4.2C (regrowth) vs. –4.9C (EL); and `Raleigh', –6.0C (regrowth) vs. –5.4C (EL). A positive correlation (r = 0.81) was observed between EL-predicted and regrowth lethal temperatures for `Raleigh', which exhibited some acclimation during the first sampling year. The EL technique consistently predicted a lower lethal temperature for `Raleigh' than for `Floratam', which corroborates field observations concerning freezing tolerance of these two cultivars.