Every grower will say the same thing: The secret to growing camellias (and azaleas) is to plant them high on mounding soil. The reason: Camellias need a happy mix of air and moisture in the soil, achieved by adding organic matter to the soil and by mounding it slightly. If you were to plant a camellia as you would anything else, the base of the plant (the crown ) might end up below ground after the soil settles; allowing that critical part of the plant to stay wet too long can be fatal to the plant. Continuous wetness probably kills more newly planted camellias than anything else, except perhaps lack of water. But once the soil is improved and slightly mounded, you can water all you wish (within reason). Excess moisture will drain away from the critical crown. Here are the steps to take when planting a camellia:
1. Water the soil several days before planting to make it easy to dig. Then make a hole several inches deeper than the root ball of the plant and about a foot wider.
2. Mix perlite and peat moss into the soil that's taken from the hole in proportions of about one-third each. Using perlite is a new idea suggested by Nuccio's Nurseries. Perlite is a major ingredient in many potting mixes, but Nuccio's has found it to be quite useful as a soil amendment for camellias and azaleas. Another, more traditional choice might be the type of treated sawdust that's sold as a soil amendment. Thoroughly mix all the ingredients until a fluffy soil results.
3. Put some of the soil mix into the bottom of the planting hole and tamp it down. Then set the camellia plant on top, so that the base of the plant (the top of the root ball) is about two inches higher than the ground level. Place the rest of the soil back in the hole and gently slope it away from the base of the plant (there will be soil left over). Let the root ball protrude a little above the mounded soil, as shown. That allows for settling, but be sure to tamp the soil down while you're filling the hole to reduce the likelihood of settling. It is important that the soil does not slope too much or it will be difficult to water. In the drawings, everything has been exaggerated for emphasis.
4. Water the soil thoroughly--with a sprinkler, not by hand--to settle the soil. During the first few weeks, you can water every few days; but then reduce watering to once a week or less. Once the plant appears established, you shouldn't even have to water even that often, since the amendments you have added will help hold moisture in the soil. Fertilize monthly until buds swell in the fall.