Abstract: The analysis of meteorological data from 1971 to 2005 showed that the winter in Haining City had been shortening and warming up during last 10 years.Warmer winter benefits the cash crop production,such as cut flowers and out of season vegetables.However,warmer winter increased the risk of freeze injury as well.Thus,prevention of freeze injury becomes extremely necessary.The analysis indicated that the minimum air temperature for avoiding first frost injury on open ground was 5~(o)C.In clear nights,the minimum air temperature inside of the non-heating green house mulched by single layer film was higher than that outside ground surface temperature,but lower than that outside air temperature.Therefore,an adjustment for the meteorological forecasted minimum air temperature minus 2.2℃ is necessary to determine the minimum air temperature of freeze injury in the single layer film mulched green house.

Key words: Warmer winter, Warmer winter, Cut flower, Vegetable, Freeze injury