Temperature Thresholds
According to Protabase, geraniums grow well in the temperature range of 65 to 95 degrees F during the growing season, and in the winter low temperatures between 40 to 50 degrees F, according to the "A-Z Encyclopedia of Garden Plants."
What temperature is too low for geraniums?
During winter, geraniums grow best with night temperatures of 50° to 60°F (10° to 16°C) but will survive if they drop to 32°F (0°C) and/or rise above 80°F (27°C), as long as they are kept relatively dry. When new growth appears in the spring, cut off all the old leaves.
What temperature should you bring geraniums inside?
The ideal temperature for growing geraniums indoors is 65 to 70 F during the day and 55 F at night.
