A Complete Analysis of the Biological Characteristics of Hydrangea

Hydrangea (Hydrangea macrophylla) originated in China and Japan. It prefers a warm, humid and semi-shaded environment.

The optimum growing temperature for hydrangea is 18-28°C, and the winter temperature should not fall below 5°C. Flower bud differentiation requires 6-8 weeks at 5-7°C; a temperature of 20°C can promote flowering, and maintaining 16°C after the flowers appear can extend the flowering period. However, high temperatures make the flowers fade quickly.

The potting soil of hydrangea should be kept moist, but it should not be watered too much; especially in the rainy season, pay attention to drainage to prevent root rot caused by waterlogging. In winter, indoor potted hydrangeas are best kept slightly dry. If too dry or too wet, the leaves are prone to rot.

Hydrangea is a short-day plant; with more than 10 hours of darkness treatment per day, it takes about 45-50 days to form flower buds. In ordinary cultivation, avoid direct sunlight; 60%-70% shading is ideal.

A loose, fertile and well-drained sandy loam soil is best. However, changes in soil pH cause considerable variation in the flower color of hydrangea. To deepen the blue color, aluminum sulfate can be applied during the flower bud formation stage. To maintain the pink color, lime can be applied to the soil.