Then temperatures may be reduced to 65F night temperature. Ventilation can begin during the day at 75F. Slightly warmer or cooler temperatures can be used to speed or slow the crop, but extremely higher or lower temperatures will delay finish. Elongation of the flower stalk is sensitive to positive or negative DIF either applied generally or as an early morning application. Humidity Botrytis can be a serious problem with Gerberas during dark, cool periods in winter when the greenhouse humidity is high. Good internal air circulation at night and ventilation in the daytime is essential.
High humidity appears to contribute to flower stalk stretching.
Light Gerberas require high light intensities for good quality plants and a high flower bud count. For this reason, they are mostly produced in the spring and summer with the greater amount of production for the spring market. Gerberas appear to respond only slightly to photoperiod. Short days tend to speed flower production while long days delays flowering. Though many growers produce Gerberas with no photoperiod control.