Azalea bonsai are great plants to cultivate. Here are some tips on their care. Satsuki azaleas are especially suitable for bonsai.
Repotting is best done just after flowering-late May to early June in temperate regions. It is also sometimes done in spring, before the buds burst. Autumn repotting is not so good. It is not necessary to repot every year, but only when the plants are found to be pot-bound.
The fertilizers used mostly are soy bean cake, rape cake, and dried fish (herring cake, etc.). These are pulverized and placed on the surface of the soil in the container, a small quantity once or twice every month. These fertilizers should be mixed in varying proportions according to the age of the plants and the season in which they are applied. Liquid fertilizers are simplest.
Water is given to young plants three or four times a day in spring, summer, and autumn; to old plants, twice a day, in the morning and in the evening. In warm weather it is good to syringe the plants.
Exposure. A sunny and well ventilated place is the best for growing Satsuki azaleas, but in the height of summer they should be in partial shade; I place them under a marsh-reed screen.
The more they are exposed to the sun, the better they grow and the thicker the trunk and branches become; therefore to the extent that one can afford the time and effort, they should be watered liberally in order that they may thrive even under the hottest sun. With the approach of freezing weather (in November most generally), keep them in a sunny place and prepare the frost cover.
Propagation. Satsuki azalea bonsai are propagated by cuttings. When the young shoots attain a length of 2½ to 4 inches and are somewhat hardened (that is in May or June), the shoots are cut off, a few leaves at the bases removed, and the bases recut on a slant and placed in water for two or three hours. These should then be inserted 1 to 2 inches apart and an inch or so deep into a good rooting medium in a cutting box. Water, let drain, and wrap box in polyethylene film. Place in full light (no sun) where they should root in 30 to 40 days.
After remaining for fifteen to twenty more days in the cutting boxes or pans, they should be transplanted into soil prepared as described above for young plants. Two weeks or so after this, fertilizer is placed on the soil to encourage growth. If liquid fertilizer is preferred, it must be very dilute, otherwise the fibrous roots often become damaged and may decay.
Application of Liquid Fertilizer
Use fish emulsion fertilizer or other commercial liquid fertilizer, diluted according to manufacturer’s directions. Do NOT over-fertilize. Liquid fertilizers should be applied three to six times a year, starting as the buds burst in spring, and every three to four weeks thereafter until mid or late summer.
How much. Use the diluted liquid fertilizer as though you were watering. Do not sprinkle the foliage with fertilizer-only the soil.
With this care, you should produce beautiful azalea bonsai.