Citrus trees are not frost hardy. The mandarin orange trees are the hardiest and can withstand temperatures down to 14˚F (-10˚C) for very short time periods. For good cultivation of citrus trees, minimum temperatures should not drop below 28˚F for extended periods of time.
Citrus needs sunny, humid conditions with fertile soil and plenty of rain. If rainfall is lacking, then substantial irrigation must be done to the groves.
Citrus trees flower in the spring, and the fruit sets after the flowering process has finished. The fruit grows during the summer months and ripens in the fall and winter.