Azalea bonsai are great plants to cultivate. Satsuki azaleas are especially suitable for bonsai.
Repotting is best done just after flowering-late May to early June in temperate regions. Autumn repotting is not so good. The fertilizers used mostly are soy bean cake, rape cake, and dried fish (herring cake, etc.). 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.
A sunny and well ventilated place is the best tip for how to grow bonsai varieties of Satsuki azaleas, but in the height of summer they should be in partial shade; I place them under a marsh-reed screen.
With the approach of freezing weather (in November most generally), keep them in a sunny place and prepare the frost cover.
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. 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.
Use the diluted liquid fertilizer as though you were watering. Do not sprinkle the foliage with fertilizer-only the soil.
So as you can see there really isn’t much to learning how to care for your bonsai. Follow the rules and your trees will bloom with wonderful flowers and thick trunks. Good luck producing your beautiful azalea bonsai.