How to grow azaleas? Master these cultivation key points

Azaleas are one of China's ten traditional famous flowers, with rich flower forms, brilliant colors, and graceful flower postures. However, azaleas have high requirements for the growing environment. If managed improperly, growth and flowering are often unsatisfactory, and they may even wither and die. Therefore, when cultivating azaleas, pay attention to the following six key points.

1. Soil. Azaleas prefer loose, well-aerated, well-drained acidic soil with a pH between 5 and 6.5, rich in humus. Mountain soil is most suitable, and leaf mold, pine needle soil, peat soil, or decomposed sawdust can also be used. Avoid alkaline soil or poorly drained clay soil.

2. Temperature. Azaleas prefer a warm and cool climate, and most azaleas have a certain degree of cold tolerance. Their optimum growth temperature is 12°C to 25°C. When the temperature exceeds 30°C, growth slows or enters a semi-dormant state; when the temperature is below 5°C, they enter dormancy; below -3°C, frost damage occurs.

3. Water. Azalea roots are shallow but well developed, with root hairs as fine as hair, and are very sensitive to water, fearing both drought and waterlogging. Generally, the soil water-holding capacity should not be less than 18%, but if water accumulates in the pot, root rot and death can also occur. Therefore, how much to water is the key to growing azaleas well. Generally speaking, it should be flexibly controlled according to the season, weather conditions, plant size, soil dryness and moisture in the pot, and growth and development needs. In winter, when the temperature drops, azaleas grow slowly and need less water, so watering should be appropriately reduced; in spring, when the temperature rises, azaleas bloom and produce new shoots, so water demand increases; in the hot summer season, water whenever the soil dries, and spray water on the ground and leaves at noon and in the evening to lower the temperature and increase humidity; in autumn, when the weather turns cool, watering should be reduced to prevent a second flush of growth, which is unfavorable for overwintering. From the perspective of growth and development, the vegetative growth stage requires more water, while during flower bud formation, watering should be reduced; too much water will cause excessive growth of branches and leaves and fewer flower buds. After flower buds form, do not water too much, to prevent the tips of the flower buds from opening and failing to bloom the following year. For watering, neutral or slightly acidic rainwater, river water, or pond water is best. If tap water is used, it is best to store it in a vat for 1 to 2 days until the chlorine evaporates before use. Long-term watering will reduce soil acidity, so when watering, add 0.2% ferrous sulfate and water once every 5 days. Or add a little vinegar and water once every half month to ensure the soil is slightly acidic.

4. Fertilization. Azaleas like fertilizer, and the principle of "light fertilizer, frequent application" should be followed. Azalea roots are fine and dense, with a weak ability to absorb fertilizer, so avoid concentrated fertilizer or raw fertilizer. Commonly used fertilizers include decomposed cake fertilizer, fish meal, or soybean milk. From flower bud differentiation to bud swelling and flowering, azaleas need about 8 to 9 months. Reasonable fertilization is the key link to making azaleas bloom abundantly and grow lushly. The specific fertilization methods are as follows:

After azaleas finish flowering, apply nitrogen-based fertilizer 2 to 3 times, once every 10 days, to promote the growth of branches and leaves. After August, the new branches and leaves become woody, which is the key period for azalea flower bud formation, so apply fertilizer based mainly on phosphorus, combined with nitrogen and phosphorus, 2 to 3 times, once every half month. At this time, if no fertilizer is applied, or if phosphorus fertilizer is lacking, or if nitrogen-rich fertilizers such as soybean milk are used, azaleas will only grow branches and leaves without forming flower buds. No fertilization is needed during the winter dormant period. Before flowering, apply a light fertilizer based mainly on phosphorus, combined with nitrogen and phosphorus, 1 to 2 times, so that the flowers are large and brightly colored when they bloom. At this time, the fertilizer concentration should be low; too strong a concentration will cause the flower buds to scorch and fail to bloom.

5. Light. Azaleas are semi-shade plants and should avoid direct scorching sunlight and dry, stuffy heat, so during care they should be placed in a semi-shaded, ventilated place.

6. Pruning. Azalea plants are low and have strong sprouting ability, with dense, overlapping branches and many sideways-growing branches, which is unfavorable for ventilation and light penetration, so attention should be paid to pruning. Pruning should be done after flowering in spring and during the transition between autumn and winter. Remove adventitious buds in a timely manner and thin out excess flower buds. Especially after the flowering period, a small number of branches may turn yellow and old leaves may fall off. Remove spent flowers in time, and cut away diseased branches, leggy branches, and branches that disrupt the tree shape, so as to improve the crown spread and ventilation and light conditions.