Camellias are among the most widely grown plants in southern Australia. The reason for this is their variety, their ease of cultivation, and their great beauty.
Most gardeners are familiar with Camellia japonica, and to a lesser extent C. sasanqua. However, there are many more species, well over 200 in fact. Several species have real garden potential because of their flower, growth habit or, in C. lutchuensis its perfume, in C. nitidissima its unusual yellow colour.
Basically camellias require shelter from the intense heat of afternoon summer sun, and protection from early morning sun in winter. Dappled sunlight provides ideal conditions for bud-set and for blooms to open effectively. However, if you cannot give camellias these conditions do not despair - there are cultivars that will tolerate more sun than others. (see recommended varieties). Generally C. sasanqua, red or dark coloured C. japonica and hybrids are more tolerant.
Camellias are best planted 2 to 2.5 metres apart in soil that is friable, rich in nutrients and preferably containing a water retaining medium such as compost or leaf mould. Plants need a soil depth of at least 40cms. A mulch of bark, cow manure, peat or other materials greatly assists, not only in the the retention of moisture, but also in keeping the roots of small plants cool in summer. Water regularly, especially well for a month after planting, and during the first couple of summers.
The two main requirements for tub culture are proper drainage and suitable growing medium. Whether soil is used or not, the mix must be open and free draining. There are many potting mixture formulas, some containing soil, some not. Most are efficient and camellias are very adaptable. However, the mix should be of an acid nature, between 5.5 and 6.5 pH. Never over-pot by putting a small plant in a large tub. Do not over water, and keep tubs on a solid surface, or raised on 'feet' to help keep drainage holes open and prevent roots from other plants penetrating the drainage holes.
With modern slow release fertilisers such as Nutricote and Osmocote, the task of keeping camellias healthy is a simple one, requiring only once or twice a year applications. A tablespoon of slow release fertiliser for a plant in a 15cm container, up to a handful for an established plant 2 metres tall will suffice.
In addition an application of Aquasol, Thrive or Zest etc. in August will give them a good start to the growing season. Yellowing of a few older leaves, which then fall off in Spring, at the same time as vigorous new growth, is quite normal and needs no treatment. Some varieties, especially those with variegated flowers, may also have some variegated leaves. If most of the leaves are generally yellow this may be a magnesium or iron deficiency, and epsom salts or iron chelates may need to be applied. For other pests and diseases consult either a good camellia book, or your local camellia nursery.