Ten precautions for growing azaleas
1. They like shade and fear direct sunlight; strong direct light easily scorches them, but too much shade will also cause poor growth and make flower buds hard to form.
2. They like acidic soil, with a pH of around 6 being more suitable; in overly alkaline soil, the leaves will gradually yellow and wither from the bottom upward, and the plant may even die.
3. With a physiological iron deficiency, chlorophyll synthesis is affected, and the leaves become smaller and yellowish-white.
4. They can generally tolerate low temperatures below 10°C, but because azalea roots are shallow and fine and close to the surface soil, they cannot tolerate heat.
5. Because the root system is fine, its ability to absorb and supply water is poor, and it fears both drought and waterlogging; it can grow well only when the air humidity is 70% to 90%.
6. Watering must be just right. If the surface is wet but the bottom is dry, the roots will be damaged and old leaves will fall early; if water accumulates and roots rot, new leaves will turn white and yellow; if water is lacking during the flowering period, the petals will droop softly; if water is lacking during the leaf-unfolding period, the central leaves will curl and the leaf color will turn yellow.
7. If nitrogen fertilizer is insufficient, the leaves will be thin and lusterless, the branches short and thin, and the flowers few and small; if phosphorus fertilizer is lacking, some leaves will turn red-purple and fall easily; if potassium fertilizer is lacking, old leaves will be grayish-green, the leaf margins yellow-green, and the leaves will develop spots, eventually turning brown, even scorched and withered, with leaves falling.
8. If the fertilizer is too concentrated or too much, it will cause reverse osmosis; the fibrous roots will shrink due to water loss, and the leaf tips and leaf margins will lose their luster and gradually scorch and fall off.
9. Poor ventilation and stagnant air will cause leaf drop.
10. They fear snow attacks and frost damage; for overwintering, around 8°C is suitable; if the room temperature is too high, they cannot go dormant, physiological activity does not decline, and nutrients continue to be consumed in large amounts, which is unfavorable for growth and development the following year.