The colourful world of the Azalea

Azaleas are one of the most admired garden specimens and perhaps the all time favourite garden shrub. Universally loved by professional and amateur gardeners alike, they provide a never ending variety of flower form and colour that is breathtaking, and truly beautiful. And one of their key advantages is that they are easy to grow, requiring little attention in the garden.

Flower forms of Azalea

The typical flower has five petals joined at the base to form a tube, giving the flower a trumpet shape. At the base of the trumpet there is an outer ring of small green sepals joined together like a collar. In the centre of the flower are five stamens - sometimes more, but in multiples of five. This arrangement constitutes a single flower. In many cases the filaments of the stamens become petal like; then this is a semi-double or double flower, depending on the number of stamens that have a petal-like form. The term "hose-in-hose" means that the outer ring of normally small green sepals become large and petal like. The actual flower appears to be inside another. The stamen filaments may also become petal-like. This makes the flower a semi-double hose-in-hose or a double hose-in-hose.

Azaleas by the nature of their delicate form and fragile beauty could lead the lay person to believe that they are difficult to grow and hard to look after. With few exceptions, this is not so. Azaleas are hardy plants, they are easy to grow, and relatively trouble free. With little care they will give the gardener many years of pleasure and a spectacular floral display. Actually, Azaleas are a series of the Rhododendron family or genus. Azaleas and Rhododendrons were originally classified as separate genera by Linnaeus in 1753 but were both classified under Rhododendron in 1834. Most Azalea botanical classifications now carry the Rhododendron prefix; for example, the popular Azalea Indica group of hybrids is botanically known as Rhododendron simsii. A close comparison of the flowers and foliage of Rhododendrons and Azaleas will show many similarities. Both prefer much the same culture. But gardeners now prefer to treat Rhododendrons and Azaleas as two different species. So, if you see reference on an Azalea label to the word Rhododendron - don't be dismayed. It will be the correct botanical identification, since discarded by all but the most erudite and professional horticulturists! There are two main types of Azaleas: evergreen and deciduous.

In Australia, the evergreen type is the one most cultivated because of its attractive green when not in flower and its ability to withstand drier and warmer conditions. However there are many hybrid groups of deciduous Azaleas. This type is best suited to the cooler moist areas of the Blue Mountains, the Southern Highlands and Canberra. They flower later than the evergreens and the flowers form in trusses. Culture and care is the same as for the evergreen types. A few hybrid Azaleas are notably fragrant.

Azaleas: a potted history

Originally the evergreen species came from China, Korea, Taiwan and Japan and the deciduous species from southern Europe, Japan, China, Canada and USA. It is not known how far back in time Azaleas actually came into being. They must be a very ancient species as history records that around 400 B.C. a company of Greek soldiers became very ill after eating honey made from nectar of the Pontica azalea (Rhododendron luteum). The plants were growing where the troops had camped along the Black Sea. Three hundred years later, a Roman army was wiped out at almost the same place, the soldiers having become stupefied after eating honey from the same source. The English introduced Azaleas into westem horticultural history whilst empire building during the 18th and 19th centuries. Many native American Azaleas were being grown in England having been sent home by adventurous colonial collectors. Great Britain and Holland, through their East India Companies, imported many Asian varieties including some from Japan via China.

By the early 1800s many species were available to European horticulturists and professionals who eagerly set to work raising hybrids from cross breeding the imported stock. In those early years, Belgium led other countries in producing new varieties. The evergreen Indica hybrids are an example of the outcome of this cross breeding and many of the originals are still available today. Throughout the 1800s, newly discovered species were being imported to Britain, Holland, Belgium and France from the Orient and as a result featured in many hybridising programmes. It was this early activity of hybridising from material gained from many and varied sources that has caused modern day confusion in identity, plant parents, and thus the exact background and breeding of many of today's hybrids.

Azaleas in Australia

In Australia, our evergreen Azaleas, both imported varieties and local hybrids, have been cross-bred and new strains developed, some of which are especially adapted to varying climatic conditions; hot summers, cold winters, drier climate, etc. such as one finds in Canberra and other country areas. Thus the newly introduced full sun hybrids have emerged which, as their name implies, revel in a full sun aspect. Other varieties prefer dappled sun and semi-shade positions in the garden. Australia is right up with world "state of the art" breeding and propagation techniques. Our country is perhaps climatically unique when compared with other countries, and for this reason has needed to breed and hybridise to suit the very stringent weather conditions applying here.