Hypericum is a tropical plant. They like warm and humid environment, so they are not adapted to the cold climate. In a cold climate, the growth rate of hypericum will slow down, the leaves will turn yellow and fall, and even cause plant death.
Therefore, we can conclude that hypericum is a plant afraid of cold and needs to grow in a warm environment. In cold climates, we can take some measures to protect hypericum, such as moving them indoors or in greenhouses, or covering them with insulation materials to maintain temperature.