Azalea by Gail Theron

by Gail Theron

Imagine living in a country where first of all, azaleas are indigenous and secondly where the interest in this floral asset is so intense that it can sustain a ISO-page full colour monthly magazine.

Well, Japan is such a country where the culture of azaleas is not only big business but also big hobby.

Types of Azaleas

I have come into contact with 3 kinds of azalea, which are:

  1. Garden azalea or Rhododendron indicum
  2. Satsuki azalea (pronounced satski) bred from indicum. There are hundreds of different types. They have been referred to as Japan's most precious offering to the West, although apart from the USA I think they are relatively unknown in the rest of the world. Satsuki means the fifth moon because it flowers in the fifth month of the oriental lunar calendar namely in May. (This corresponds with our sixth month i.e. June). In Japan growing satsuki as bonsai is a separate activity from growing other bonsai; there are separate shows and clubs for the cultivation of satsuki alone.
  3. Kurume are hybrids that were first bred in the Kurume district in the 1830s. They have small leaves and flowers. Colours range from white through shades of pink to red. Azaleas like semi-shade conditions and they like water as long as the soil drains well. Azaleas grow best in a slightly acid soil e.g. a mix of 60% compost, 40% coarse gravel or chips and S cups of peat to about 8 litres of soil mix.


Potting is done after flowering. It is said that azaleas don't like to have their roots trimmed, but because the roots grow to a fine matted mass, it is sometimes advisable when potting for the first time to gently wash all the old mix off to enhance growth in a fresh medium. If the tree is healthy potting is only necessary every 2-3 years; azaleas like to be snug in the pot. When repotting, wedges should be cut out of the rootball to minimise disturbance of the roots and fresh soil can be worked into the cut out areas.


Azaleas can be shaped and pruned into most of the usual styles, including root-over-rock and exposed root (neagari).

Design pruning is best done in August-September. They will break back on hard wood as long as some foliage is left. Prune back to shape after flowering and lightly trim or nip as is necessary during the growing season. Some growers advise not to let the tree flower every year, but to rest it by trimming off the flower buds.

Azaleas can be wired but because they are more brittle than other trees, care should be taken, also the bark is very thin and can be easily damaged. Best time to wire is late spring or autumn and wiring should be checked carefully for wirebite especially in spring. Keeping the tree in shade and withholding water for a day or two will also make it more pliable. Rather use two strands of wire than one thick one.


From early spring feed with a balanced fertilizer like Nitrosol to promote growth of shoots and leaves. Feed with a higher potassium fertilizer like 3-1-5 prior to flowering and stop feeding during flowering. Resume feeding with a high nitrogen fertilizer after flowering.

Pests and Diseases

Azaleas are quite resistant to pests and diseases. Treat fungus, which may affect leaves and flowers with Funginex. Mites can be eradicated with Kelthane and snout beetles with Garden Ripcord.


Propagation of azaleas is by either using cuttings of new shoots or last year's growth. The best time for making cuttings is in early summer. Air layering or ground layering in spring is also effective ways of increasing your stock.

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Random Bonsai Tip

If a tree lacks a branch in a specific place you could in arch or approach graft a branch in the required area or thread graft through the trunk using a long shoot of the same plant.