Country of Origin : Japan
Bonsai Styles : Informal upright
Zone : 5 – 8
Satsuki azalea bonsai trees from Japan are in a class all their own. Bonsai Satsuki azaleas are perhaps the most popular flowering bonsai in Japan.
In addition to the smooth, orange, brown bark and small, glossy leaves that make wonderful bonsai, the mass of beautiful flowers produced on the tree elevate the bonsai to a completely new level. It is a wonderful sight to see a Satsuki azalea in full bloom.
Satsukis bloom in midsummer, at the ends of short current shoots, rather than in spring like garden azaleas. These flowers can last on the tree for about a month.
The infinite array of flower colors and patterns is astounding.
Several varieties have self-colored flowers, while others bear flowers of two different colors on the same tree. There are even varieties with pink-and-white variegated flowers.
There are many Rhododendron varieties used to make Rhododendron bonsai. Some of them are listed below :
- Rhododendron indicum (Azalea indica) – Satsuki Azalea. These are probably the most preferred variety for making a bonsai. It is an evergreen azalea. The leaves of these plants are narrow, small, and dark green. In early summer, they bloom in a variety of colors, including white, pink, red, and purple. On the same plant, you may find different colors, stripes, speckles, or blotches.
- Rhododendron obtusum – Japanese kurume azalea. These are probably the second most popular variety used to make Rhododendron bonsai tree. Having red flowers and small, shiny leaves, it is an evergreen or semi-evergreen plant.
- Rhododendron indicum ‘Hakurei’ – Satsuki Hakuret. Creamy-white flowers grow on these plants, along with small, glossy, the leaves are dark green and pointed.
- Rhododendron indicum ‘Kaho’ – Satsuki Kaho. The shrub has flowers in soft, pale shades of pink and their shape resembles a trumpet.
- Rhododendron ‘Eikan’ – Eikan Satsuki Azalea. These are also some of the most prized varieties used for making Rhododendron bonsai tree. White, pink, and bicolored flowers can all appear on the same branch at the same time.
- Rhododendron indicum ‘Chinzan’ – Satsuki Chinzan. This plant produces bicolored pink flowers with red colored throat. It has glossy, small narrow leaves.
- Rhododendron indicum ‘Kazan’ – Satsuki Kazan. This plant produces red flowers. It has small leaves and has a compact growth habit.
- Rhododendron indicum ‘Kinsai’ – Satsuki Kinsai. This plant also produces red flowers, however with deep cuts. It has small narrow leaves.
- Rhododendron indicum ‘Korin’ – Satsuki Korin. This plant has a compact shape. It produces small pink colored flowers.
Best location to keep Satsuki Azalea Bonsai
Azalea bonsai tree experiences fatigue in hot climates.
Satsuki azalea bonsai tree can tolerate full sun for a short while. However it is best to keep the tree in semishade, or even in complete shade during midsummer.
When kept in semi shade, the flowers on the tree last for a longer time. Also, the leaf color is much better.
A maximum temperature of 86°F (30°C) in the summer and a minimum temperature of 32°F (0°C) in the winter is ideal.
The satsuki azalea survives without winter protection in mild temperate climates.
For short periods of time, they can tolerate temperatures as low as -7°C (19°F), and an open shade structure can be adequate protection. However, when the temperature goes below this temperature, move the bonsai container to a heated or unheated shed.
Protect the bonsai tree from heavy rain.
Propagation of Satsuki Azalea
Satsuki Azalea tree can be propagated by using softwood cuttings in early summer.
It can also be propagated by air layering in early summer.
Watering Satsuki Azalea Bonsai
It is vital that the bonsai soil does not become even partially dry. Protect Azaleas from drought as they are highly sensitive to water scarcity. The roots will become dry and brittle in dry soil.
Throughout the year, water regularly and liberally, especially when the trees are in bloom.
Take care not to accidentally splash water on the petals while watering, since they are easily damaged. However, you can use a gentle mist spray.
The soil should be moist, but not soggy.
Read watering bonsai tree for more details about immersion technique.
Using rainwater is the best option. Azaleas don’t like lime and will deteriorate rapidly if soil calcium levels are allowed to rise.
If rainwater isn’t available, use lime-free tap water instead. You can also treat the soil with a soil acidifier. Read more about bonsai fertilizer.
Wiring Satsuki Azalea Bonsai
You can start wiring your Rhododendron bonsai from fall or winter.
Wires can be left on the plant for almost an year.
Pruning Satsuki Azalea Bonsai
When to prune Satsuki Azalea bonsai?
How to prune Satsuki Azalea bonsai?
After the flowers have finished blooming, you should deadhead them as soon as possible.
This is also a good time for pruning as the leaves have not hardened at this point.
The laterals (secondary shoots) should be pruned back to two pairs of leaves.
Also at the time of repotting, you can remove overcrowded and dead branches.
Pruning can also be done in early spring. However it should be only done if absolutely necessary.
Early in the spring, Japanese growers sometimes prune the bonsai tree hard, depriving themselves of the season’s flowers in order to promote better branching and correct the tree’s bonsai style defects.
Pinching Satsuki Azalea Bonsai
The Satsuki azalea bonsai tree is not typically pinched.
However, to keep the tree in good shape, you can clip the tips of overextending shoots. It is important not to pinch all the growing tips in summer or you will lose all your flowers the following year.
Repotting Satsuki Azalea Bonsai
When to repot Satsuki Azalea bonsai?
Rhododendron bonsai tree can be repotted as soon as the flowering stage is completed.
However, when repotting in temperate countries, it is best to do it in the spring before flowers bloom.
Young trees can be repotted every 2 years.
Mature trees (about 10 years old) can be repotted in 4-5 years. Use a deep container.
The repotting schedule depends on whether the roots are pot bound or not.
Satsuki Azalea Bonsai tree prefers acidic soil.
You can use a basic free-draining, lime free bonsai soil mix as a potting soil. You can also use a soil acidifier.
You can also use a soil mix consisting of 30% grit and 70% organic matter. For organic content you can use ericaceous compost or sphagnum peat.
Must Read: Bonsai Soil Recipes
Must read : Choosing the right bonsai container
Feeding Satsuki Azalea Bonsai
A weak solution of balanced feed should be applied every two weeks until flowering begins, and then feeding should be stopped.
Once flowering is over, fertilize with a low-nitrogen fertilizer until the end of fall.
Make sure any fertilizer you use is suitable for ericaceous plants, or use organic fertilizer instead.
Rapeseed fertilizer is commonly used by some growers.
As mentioned earlier, these plants love acidic soil. So, you can also use a soil acidifier.
Read more about bonsai fertilizer and its application.
Diseases and pest of Satsuki Azalea Bonsai
Vine weevils can pose a serious issue for Satsuki Azalea Bonsai trees. Although vine weevils can chew on leaves, their larvae are much more dangerous for the roots. Before repotting, you should check for the presence of vine weevil larvae. Kill and remove them as soon as possible.
Water some parasitic nematodes in the bonsai soil in late spring.
Rhododendron bugs and leaf hoppers can be treated using an insecticide spray. Pick off and burn any foliage affected by azalea leaf gall.
Scale insects can affect the tree. On young shoots, aphids cluster sometimes, but can generally be removed manually. If the infestation persists, you can apply a systemic insecticide.
Satsuki Azalea bonsai care
These plants are very fussy about the soil. They will not grow if the soil is not the right kind. Lime in soil or water can damage trees by preventing them from accessing nutrients. When the leaves turn yellow, the tree slows down and eventually dies. Avoid using alkaline fertilizers.
Wire training can cause shoots and branches to snap without warning due to their brittleness. So wire the bonsai carefully.
They can grow vigorously after pruning. Wire training must be carried out before midsummer because the long, slender red shoots grow up to 4/3 of an inch in a day.
In order to maintain plant hygiene, it is imperative to remove all dead or damaged flowers as soon as possible.
What to look for when buying Satsuki Azalea Bonsai
Buying a Satsuki bonsai tree in early to mid summer is a better idea. This will give you ample time to think about which color you would prefer.
You should not rely solely on the label to tell you the color of the bloom. It will only give you a very rough indication.
Try and purchase a bonsai specimen with a decent branch structure.
Purchase a bonsai which has a thick and tapered trunk. These examples should not be hard to find as the tree can achieve such truck pretty easily.