Bonsai Satsuki Azalea Growth and Care
General Background:
The Satsuki azalea is one of the most sought after and satisfying of all bonsai subjects. First and foremost, among its reasons for popularity is that it has a prolific number of gorgeous flowers when in full bloom. In addition to being a delight for the eyes, the plant adapts well to container cultivation, trunks up substantially in a relatively short period of time, adapts well to substantial root pruning and easily develops new buds with exceptional vigour on old wood. Azaleas, as the botanical name implies, are members of the Rhodendron family. Azaleas, however, are smaller leaved in stature, thus making them prime candidates for the bonsai artist. Satsuki is a Japanese term which means "fifth month", or late spring—the time that most Satsuki go into bloom. Satsuki have become the most popular for bonsai followed closely by the Kurume varieties. There are literally hundreds of different varieties of both species, mostly grouped according to the shape and colours of their flowers.
Trees Features:
The Satsuki Azalea is a popular choice among Bonsai. This particular plant is very hardy and produces magnificent flowers ranging up to seven inches in diameter. Of all shrubs with flowers, the Azalea is by far the most dramatic with brilliant blooms of radiant colours blooming in late spring. While there are many species of Azalea, the Satsuki, or Rhododendron indicum is easily one of the most popular, featuring an excellent low, twiggy habit with lovely funnel shaped unscented flowers in whites, pinks, reds and purples. The Satsuki is identified by two blossoms on the end of the terminal; they also have slightly hairy leaves budding out freely from even fairly old wood. Because the azalea is highly coveted in Japan, there have been hundreds of different varieties, in every colour except yellow, bright orange, and true blue.
Temperature:
Keep outside until temps drop below 9 degrees, taking care to always protect your Bonsai from the stress of frost, and then move into a frost-free shed. Once dormant, it should be placed in a protected location and mulched up the rim of the pot. Mice and rabbits find the soft bark of the azaleas particularly tasty so keep that in mind when you select your storage spot. For those who want to keep their bonsai indoors year-round, the Satsuki Azalea Bonsai is happy to oblige; a cool window and plenty of light is needed for successfully keeping an azalea indoors during the winter months as is the need for frequent misting and high humidity.
Lighting:
This lovely Bonsai will do well in a bright location that is filtered from direct sunlight or with about half a day of direct sunlight as it dislikes being kept in full sun, which will also fade and ruin the flowers and damage the roots; because they demand cooler temperatures to stay healthy. It can take full sun for a little while, but will look best when in a light shade or bright diffused indoor light.
Watering:
Azaleas do not like any hint of dry soil so be sure to keep the soil evenly moist at all times. The tree should be watered at least once a day throughout the growing season to ensure that the soil mass remains moist— not soggy. Azaleas do not like to dry out; if allowed to do so, the fine fibrous roots will quickly desiccate and die. When you water, it is best to try to use lime free tap water or rainwater because Azaleas hate lime. It becomes especially important in hard-water areas to water with rainwater only to avoid lime deposits building up in the soil. Though not preferable, if hard water has to be used on occasions, the pH value of the compost can be adjusted by applying white vinegar to water once a month. Mix at a rate of 1 tablespoon to a gallon of water. Azaleas like perfect drainage as air is essential to ensure that rot does develop in the root ball.
Fertilizing:
Feed your azalea at least every other week in the spring time until the flowering period is over. Use a week solution of a balanced organic fertilizer for acid loving/lime hating plants until flowering starts then be sure to stop, otherwise feeding during blooming will result in loss of flowers and flower buds at the expense of leaf growth. Thereafter, monthly feedings will be adequate. In the late summer or early fall, reduce nitrogen from the fertilizer mixture and begin increasing the amounts of phosphorus and potassium. This will help the tree to set buds and blossoms for next season.
Pruning / Training:
Azaleas have particularly brittle branches and tender bark which makes the use of aluminium wire desirable, aluminium wire is softer and will work better than copper: in fact, aluminium wire was specifically developed for use by Japanese azalea growers, although today, it is widely used for all types of bonsai. Plastic tape or raffia can also be used to protect sensitive bark. It is important to make clean cuts with a sharp tool and to seal all larger wounds to the tree with Lac Balsam or some other wound sealant immediately. After the tree finishes flowering, it is important to remove all the dead flowers at the flower's base, to prevent the tree from forming seed pods and will encourage new leaves. The best time to wire and shape is in November, when major work can be done. Light wiring can be done at other times as needed, but with care. The azalea is very brittle and must be allowed to dry out for a week before attempting heavy bending. To keep your Azalea healthy and happy, you want to remove any dead flowers and leaves immediately. To enhance the overall structure of the Azalea, it is important that yearly growth be removed or trained as soon as the flowering season ends. Then, any secondary shoots should be pruned in midsummer. Azaleas respond well to hard pruning and if pruned back to a stump after flowering will bud-back prolifically and can be shaped in just about any bonsai style. With a distinct trunk, you often see the Azalea trained in the shape of a tree. The most common styles used include the root-over-rock, semi-cascade, windswept, slanting, and informal upright, which look great on both twin and multiple trunk Azaleas.
Insects / Pests:
Azaleas are susceptible to whiteflies, scale insects, caterpillars, aphids, mildew, bud blast, rust, leaf gall, petal blight and lime-induced chlorosis (if soil not acidic enough). Never spray open flowers with insecticides or fungicides as this will cause them to wilt and fall. Most insects can be combated with a solution of 1tsp dish soap to 1 litre warm water. Spray liberally until solution runs off leaves and rinse well with water. Repeat as needed.
Propagation:
Because of their ability to bud back readily on old wood, azaleas are seen as very "collectable", particularly from overgrown foundation plantings around private homes. Collected trees with massive trunks can be cut back almost to stumps and will still develop hundreds of new shoots and branches if cultivated properly. You can propagate your azalea from softwood cuttings taken in early summer, after flowering has finished.
Repotting:
Azaleas like a somewhat acidic soil content. It is therefore advisable to add a little more peat to your potting mixture when transplanting azalea. Azaleas develop fine, fibrous feeder roots with very few larger tap roots. They withstand substantial root pruning, although it should be done in the early spring, just before or after the tree finishes flowering. If you choose to transplant before the tree flowers, it is advisable to remove all flower buds so as to avoid placing an unnecessary strain on the plant. The roots systems grow vigorously and will probably need transplant and root pruning ever two years. The bottom of the old root ball must be cut out at each transplanting. This is done by cutting a cone shape into the root ball, extending right up to the bottom of the trunk. The roots are thickest here and must be removed to prevent rot caused by lack of air or poor drainage. The best time to repot is after blooming is finished. Repotting can also be done in the late fall, but with care. Flowers take a tremendous amount of energy from the plant so it is best to remove all the flowers, old and new, and the remaining buds, all at the same time; Taking this step will ensure that the following year, the buds will open at the same time. If you see the flowers coming too soon in the spring, remove the largest two or three buds before they open, which will slow down flower development some. Also try putting the plant in a cooler and slightly shadier location.
Additional Comments:
Azaleas flower prolifically which can completely obscure the tree itself which is why many enthusiasts remove pockets of buds around the tree to allow areas of fresh green leaves to be enjoyed through the masses of colour.