In Whanganui camellias generally grow very well with some wind and part shade protection. Camellias prefer soil that is well drained but moisture retentive and slightly acidic. Roots need a cool root run plus ample air in the soil while the slight acidity ensures that all the nutrients needed for healthy growth will be available.
The best soils range from good loam to sand well enriched with good quality organic compost. Clay soils 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 down slope and the roots are less likely to be in prolonged saturation.
Basic Planting Guidelines
Sand and Loam Soils; the planting hole should be a little more than double the depth of the root ball and approximately 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 slow release fertiliser tablets added. When you finish planting make a watering basin by forming a ridge of soil around the outside of the filled in hole. Add a mulch over the soil around the plant and just covering the top of the root ball. The watering basin ridge will help to keep the mulch in place.
Heavy Soils; if you have heavy soils here are three options for planting;
A) Use organic matter or compost to improve a broad shallow saucer shaped hole in the soil, plant the camellia high with the top of its root ball above the soil surface and mulch heavily. The elevated planting will allow better drainage of water from the root zone.
B) If you want to plant several camellias 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 pumice granules or sharp river sand that will be more to the roots liking.
C) Plant in Containers; they 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 quality potting mix such as 'Natural Bark Potting Mix' adding a slow release 'Acid Fertiliser', 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.
Gareth Carter is General Manager of Springvale Garden Centre