Key points for azalea cultivation: suitable temperature is crucial

Azaleas are damaged when the temperature is too high or too low. Only under suitable temperature conditions can they develop and grow rapidly and robustly. Therefore, attention to the suitable temperature for azaleas should be a key point in azalea cultivation and management.

Azaleas should be moved into a room with a temperature no lower than 5°C around Frost's Descent. During overwintering, different varieties have different temperature requirements. For example, summer azaleas should not be below 5°C, spring azaleas around 10°C, and Western azaleas about 8-15°C. It should be noted that below 3°C, varying degrees of cold damage may occur depending on the variety.

When moving outdoors in spring, it is suitable to maintain 15°C at night and around 18°C during the day. The suitable temperature during the growing period is 12-25°C, so spring and autumn are the periods of vigorous growth. After summer begins, if the temperature exceeds 35°C, new shoots and new branches grow slowly or enter a semi-dormant state with extremely weak physiological activity. If the temperature continues to rise, it can cause the protein inside cells to denature and coagulate, with the risk of heat death at any time.

To make them bloom earlier, spring azaleas can be moved indoors to a sunny spot in December, kept at around 15°C, and sprayed with water on the leaf surfaces frequently, which can make spring azaleas bloom as early as February.

Azaleas require a day-night temperature difference of around 6°C. If the daytime temperature is too high or the nighttime temperature is too low, both will affect the vegetative growth and reproductive growth of the flowers.

The suitable temperature for rooting azalea cuttings is around 20°C, and they can take root after two months. When the temperature exceeds 30°C, a shade curtain must be immediately put up to lower the temperature, otherwise rooting will be seriously affected.