The showy Camellia Margaret Davis has peony-like blooms. Photo / Supplied
If you want a plant that is green, keeps its form without regular trimming, is not susceptible to many pests and diseases, provides tidy structure, has lovely flowers and is generally pretty hardy, then look no further than a camellia.
Camellias are suitable for growing in containers on the patio and in the garden. Many varieties flower during the winter months when there is little other colour in the garden, which is another bonus for this winner of a plant. The flowers may be single, double or semi-double, and pink, red, sometimes white or a mixture of all three. There are a few creamy-yellow varieties too.
In Whanganui camellias generally grow very well, with some protection from prevailing winds and with some shade offering protection from the hottest of the summer sun.
Camellias grow best in fertile soil conditions, preferring soil that is well drained but moisture retentive, and slightly acidic. The best soils range from good loam to sand well-enriched with peat (good-quality organic compost, too, can be used, but beware many bagged composts have an alkaline pH so are not suitable).
Sand and free-draining loam soils: The planting hole should be a little more than double the depth of the root ball and about three times as wide. To the soil that you remove from the planting hole, thoroughly mix in a roughly equal amount of organic compost or peat with a slow-release fertiliser such as Ican Slow Food.
Heavy and wet soils: Use organic matter or compost to improve the soil quality and plant the camellia high, with the top of its root ball above the soil surface and mulch around it to cover any exposed roots. The elevated planting will allow better drainage of water from the root zone. If you want to plant several camellias in these soil conditions, a good procedure is to create raised beds, filling the beds with a mixture of soil, good-quality compost and free-draining material such as garden mix containing pumice granules that will be more to the roots' liking.
Containers: Camellias are one of the best plants for long-term residence in containers, whether you want just one or two as accent plantings or a larger, portable collection. Use a good potting mix such as Natural Bark Potting Mix or Ican Premium Potting Mix available from the garden centre. Put enough into the container so that the top of the root ball is about 30mm below the rim of the container. Fill in around the roots with more potting mix, firming by hand, and water thoroughly until the water flows freely from the drainage holes.
Clay soils found on Durie Hill and parts of St John's Hill, though they are moisture retentive, offer the least-friendly conditions for camellia roots because the particles are so small and tightly packed that drainage is extremely slow and roots can remain saturated and suffocate from a lack of soil air, causing death of the plant. This especially occurs on level clay sites. Clay soils on a slope or hillside can be more accommodating because drainage is downslope and the roots are less likely to be in prolonged saturation.
You can improve the drainage and aeration of clay soils by adding copious amounts of organic matter and gypsum, a neutral pH form of lime that flocculates fine clay soil particles into a more crumbly structure. The problem often remains that the clay soil around the improved soil will prevent the water from draining away quickly enough and can create a "bathtub" effect.
Camellia types
Camellia japonica: These are the camellias best known to us. There are thousands of named cultivars of all flower forms and colours. They are particularly hardy. Their foliage is glossy deep green. A careful selection can provide continuous flowering for up to six months of the year. Flower sizes vary from miniatures under 5cm across to the flamboyant 20cm doubles, all great for a garden display or floral art. Popular varieties include Takanini (deep dark red) and Brushfields Yellow (white with a pale yellow centre). Camellia Waterlily is a hybrid with medium-size formal double blooms of bright pink. Camellia Quintessence is a hybrid that flowers pure white with a yellow centre. It has a miniature spreading growth habit and a sweet musk fragrance.
Camellia reticulata: These are the largest-flowered of all camellias. The plants are often not as tight in their growth habit. They are not as widely grown or available. Well-known hybrid varieties include Dr Clifford Parkes (scarlet orange) and Dream Girl (delicate pale satin pink).
Camellia sasanqua: These are very hardy and are the first flowering of the camellia season beginning in April. By the time the japonicas begin to take centre stage, they have mostly finished flowering. They produce an abundance of blooms, usually smaller in size than japonica types but often fragrant, in a full range of colours of white, through pink to red. They have great versatility. Some varieties are highly desirable as hedge plants, some are more spreading in their growth habit and can be used as ground covers in semi-shady positions. Some can also be easily espaliered. Smaller-leaved varieties also look great trained into topiary forms. Sasanquas are more tolerant of sun than japonicas and grow well in Whanganui. Popular varieties include Setsugeka (pure white with yellow stamens), Early Pearly (pure white) and Yuletide (orange-red). The sasanqua-type camellias are ideally suited to be grown as a flowering hedge or screening plant.
• Gareth Carter is general manager of Springvale Garden Centre