Few flowering shrubs can match the camellia (Camellia spp.) for colorful, delicate flowers and glossy, green leaves. The genus includes over 200 species, including the sasanqua camellia (Camellia sasanqua), with showy red flowers, and the Japanese camellia (_Camellia japonica_), renowned for its flowers and available in more than 3,000 cultivars, varieties and hybrids.
Sasanqua camellia and Japanese camellia are evergreen shrubs that are hardy in U.S. Department of Agriculture plant hardiness zones 7 through 9 and 6 through 9, respectively. Like all camellias, they thrive when planted properly and given partial shade, sufficient moisture and a bit of extra attention now and then.
Site Selection and Planting
You can plant new camellias either in spring or fall. If fall tends to be cool where you live, then it's safer to plant in spring to give the plants plenty of time to produce new roots before cold weather arrives. Choose a site that is sheltered from wind and in partial shade; dappled, shifting shade under a tall tree is ideal. The north side of a building is also a good location because it protects the plants from hot afternoon sun exposure. For the best display, give the plants lots of room to spread. Determine each plant's width at maturity, which should be on the plant nursery label. Then set each plant's center about one-half of that measurement from all other large plants. For example, the cultivar 'April Tryst' (Camellia japonica 'April Tryst') is 3 to 4 feet wide when mature; so allow about 2 feet of space in all directions from that plant's center. It's hardy growing in USDA zones 6 through 9.
Dig a hole that is at least two times the width of its respective plant's root ball. Then add about 2 inches of compost to the bottom of the hole, and mix it into the soil. Set the plant in the hole at a depth that keeps it at the same soil depth at which it was in its nursery pot. Fill the remainder of the hole with soil, tamp the soil and flood the root ball area with water to ensure no air is trapped around the roots.
Soil Acidity, Moisture and Fertilizer
Camellias do best when grown in soil that is slightly acidic, with a pH level of 5 to 6. For the best results, use a commercially available test kit to determine the current pH level of your soil, and then adjust it as needed before planting. For example, add 0.4 pound of sulfur to lower pH from 7 to 5 in 10 square feet of planting area. If your soil is extremely acidic, with a pH lower than 5, then you could add finely ground limestone to raise the pH level, but it's best to do that task the season before planting, allowing time for the soil to adjust. Retest the treated soil before planting to check its pH.
Camellias need a regular supply of moisture, especially during the first three years after they were planted. Check the soil's moisture level regularly with your finger or by digging carefully with a small trowel -- without disturbing surface roots, and provide extra water whenever the top few inches of soil are dry to the touch. Adding 2 or 3 inches of organic mulch under each plant's canopy also helps conserve soil moisture, but keep the mulch about 4 inches from each plant's center to discourage fungal problems. Never allow a camellia to dry completely during hot weather; dryness can prevent buds from opening.
Camellias are light fertilizer feeders but benefit from fertilizer in spring, after flowers have fallen from the plants. They can be fed again in mid-summer if their growth is slow and their leaves turn a lighter green. Use a fertilizer designed for camellias and other acid-loving plants; an example is a granular, 4-3-4 formula. Apply 4-3-4 fertilizer at a rate of 1 pound per 10 square feet of area, but check your fertilizer's label for further directions. Apply the fertilizer when the soil is moist to avoid burning the plants' roots, and water the soil well after applying fertilizer.