Azalea as bonsai are stunning due to the abundant flowers which come in all colours, shapes and sizes. There are many varieties so species selection is key to ensure that you have the one you want. They belong to the Rhododendron genus which is part of the Ericaceae family.
One of the most common Azaleas is the evergreen or semi evergreen Azalea species (Satsuki) and there are numerous varieties of these and too many to list. The majority of varieties have come from Japan and relate to the Kurume Azalea which originates from Rhodendron kiusianum. Some forms appear dwarf in appearance while others still retain their statuesque characteristics.
The majority flower from April through to May and the flowers can be so dense in number as to obscure the trunk, branches and foliage.
They tend to prefer full sun whilst having moist roots but like to be sheltered from winds and partial shade suits some clones avoiding bleaching of the leaves and flowers. Also they need to be protected from frost over winter and from heavy rain during flowering. They should be kept moist and watered throughout the growing season daily and where possible mist foliage to increase humidity.
Feed until they flower and again once flowering has finished up until early autumn and use a fertiliser suitable for acid soil loving plants as they prefer ericaceous soils.
Repot after they have finished flowering after May and this can be done annually or when necessary subject to the root development. For soil, use a lime free mix like Kanuma or ericaceous (acid) soil.
Prune after flowering also and dead flowers carefully once they had faded before then pruning the current growth shoots and secondary shoots. The pads on Azalea can get dense and over crowded so it is important to have a good structural and thinning pruning session post flowering to ensure the flower buds for the following year have space to develop into.
An example of one of the hybrids is ‘Kirin’ which has a deep rose, shaded silvery rose for the flower colour.
A very common Satsuki Azaleas ‘Hakurei’ which has creamy flower buds with white star like flowers and slender evergreen leaves.
They come in so many styles and a particular favourite is the exposed root which is fabulous.
Plus there are a few tropical varieties which require warmer temperatures to thrive to look out for if you only have space indoors for a bonsai, for as a rule the majority of Rhododendron and Azalea live outside in the UK but need shelter during cold winters like a cold greenhouse.
Here are a few images of Azaleas in all their fabulous forms and colours.