When these beautiful and early-flowering, evergreen shrubs first arrived in Britain in the mid eighteenth century they had already been highly developed by the Chinese and were available in numerous single, semi-double and double-flowered varieties. At that time they were considered far too tender to be planted outdoors and shared the orangeries and conservatories in which other exotic ‘greens’ were cultivated.
Gradually, however, it dawned on gardeners that most camellias were almost fully hardy and it was only their flowers that were at risk. Planted in suitably sheltered places, and in particular in woodland gardens which, by the late nineteenth century, were being made all over the place primarily for, they were quite happy in the open.
Today camellias are in great demand both for this purpose and for cultivation in pots, tubs and other containers as terrace and patio plants.
The number of varieties is legion and has been swelled by the introduction of other species in addition to the original Camellia japonica, and the hybridization of these with existing varieties. The Williamsii hybrids, for example, are the result of crossing Camellia japonica with the smaller-leaved, thinner-stemmed Camellia saluenensis. ‘Donation’, a double pink-flowered variety of this parentage, has become one of the most popular of all camellias because it produces flowers with astonishing freedom; successive batches of flowers will open even after earlier ones have been spoiled by frost.
A very large-flowered species with a rather lax habit, named Camellia reticulata, has given rise to another race of camellias notable for the size and beauty of their flowers but these are, in general, a little more tender than Camellia japonica and Camellia williamsii varieties and, except in mild districts, may need to be trained against walls or given specially sheltered places.
The same is true of the lovely forms and hybrids of Camellia sasanqua, not least because they can begin flowering in autumn and continue most of the winter if the weather is kind.
The colour range of camellias is not great, from white and palest pink to crimson, but flower size and form are varied, from singles with a single circle of petals and a central tuft of golden anthers to fully double flowers which may be completely formal, almost as if carved out of wood, or completely informal or anything between these two extremes. There are anemone-centred camellias, peony-flowered varieties, semi-doubles, large-flowered, medium-flowered and small-flowered kinds. The only serious lack is of camellias that flower really late, in May and June — rather than March or April — when their flowers would be much less at risk from frost.
Like rhododendrons, camellias dislike lime but they have a greater tolerance of soils that are near-neutral or only very slightly acid. They are also far more tolerant of dryand seem to be almost immune to attacks by the honey fungus (Armillaria mellea) which does a lot of damage to rhododendrons. They enjoy dappled or intermittent shade but will also grow in full sun, though less vigorously and often with yellowed leaves. The two genera combine well and are frequently planted in association, the camellias preceding the rhododendrons in their main flower display.
Leaves of all camellias are evergreen and most are dark green, shining and handsome, and make first-rate foliage shrubs. They transplant well and are tolerant of very hard pruning in May, which can be useful if they become overgrown but should not be taken advantage of unnecessarily since it reduces or even eliminates the flower display the following year. If a few stems are cut with flowers for indoor decoration this is usually all the pruning that camellias require.
They benefit from annual top dressings of peat or leafmould supplemented by moderate applications of a compound fertilizer, preferably one containing minor elements such as iron, manganese and magnesium as well as nitrogen, phosphorus and potash. They suffer very little from either pests or diseases but scale insects, looking rather like minute limpets, can attach themselves to stems and leaves and should be removed by sponging with soapy water or spraying with diazinon, malathion or petroleum-oil insecticide.