Celery is a semi-cold-resistant vegetable, especially during the vigorous growth period of the plant. The optimal temperature is 15-20°C. Above 25°C, it will not grow well, the fiber will increase, and the quality will decrease. Therefore, it is produced in the open field from September to October. Autumn is crisp, the temperature is suitable, and the light is sufficient. As long as fertilizer and water are supplied, celery will achieve high yields and the quality will be particularly good.

Celery has a wide adaptability to temperature in its seedling stage. Seedlings with 5 to 6 leaves can withstand high temperatures above 30°C and low temperatures of -4 to -5°C, and will not freeze to death even at temperatures as low as -10°C for a short period of time. Taking advantage of the wide temperature adaptability of celery seedlings, production often arranges the seedling stage of celery in summer and winter to survive adverse conditions. The temperature adaptation range is narrow when entering the adult plant stage, and neither high nor low temperatures are suitable. The best growth temperature is about 20°C. Under high temperatures, the growth is poor and the quality deteriorates; under low temperatures, especially when the temperature drops below -3°C, the petioles will crack due to freezing. Once it falls over, it has no edible value even after slow thawing. Therefore, during autumn and winter cultivation, cold protection and heat preservation work must be done according to weather changes before harvesting.

When celery enters its vigorous growth period, in addition to paying attention to day temperature, it is also necessary to control a certain night temperature so that the temperature difference between day and night is not less than 10°C. This is conducive to nutrient accumulation, resulting in enlarged leaves, thickened petioles, and developed root systems. .