Camellias are evergreen shrubs that bloom during the late fall and early winter. Japanese Camellias (Camellia japonica) have flowers in shades of red, pink and white, and leathery leaves up to 4 inches long. Sasanqua Camellias (C. sasanqua) has smaller blooms and leaves. To lessen the chance of disease, gardeners should observe proper planting procedures and care. Camellias require regular watering and fertilization, and grow best in acidic, well-drained soil in partial shade. Prune diseased plant parts and remove debris from around plants to prevent the spread of diseases.
Leaf galls on Camellias, caused by the fungus Exobasidium camelliae, occur during spring growth. Infected shoots and leaves thicken, become fleshy and turn pale pink or almost white. When the galls mature, they rupture and release a mass of whitish spores. The galls then turn brown and harden, and may drop off. Leaf galls seldom damage Camellia plants. Remove and destroy the leaf galls to reduce the severity of the infection the following year, and apply a fungicide according the manufacturer's instructions to control leaf galls.
Camellia Flower Blight
Camellia flower blight is a serious disease caused by the fungus Ciborinia camelliae. The disease occurs in the spring with small irregular brown spots on the petals of the flowers. The spots spread quickly and cover entire flowers. An infected flower will turn brown and fall off in 24 to 48 hours. Remove and destroy infected flowers, as well as debris from around plants. A soil drench applied at the rate recommended by the manufacturer in late December or early January may reduce the impact of the disease.
Camellia Dieback and Canker
The fungus Glomerella cingulata causes Camellia dieback and canker, a serious disease. Initially, the foliage suddenly turns yellow and wilts, followed by dying branch tips. Gray patches of fungus grow on infected bark and stems, and cause cankers that can girdle the affected areas. Prune and destroy the diseased plant parts. Applications of a fungicide during wet periods and during leaf drop, at the rate recommended by the manufacturer, may reduce the intensity of the disease.
Root rot, caused by Phytophthora cinnamomi, is also known as foot, collar or crown rot. Infected roots of Camellia plants turn reddish to dark brown; healthy roots are white. All the leaves turn yellow, and the entire plant loses vigor and wilts. A Camellia plant with root rot may die suddenly or linger for several years. Japanese Camellias are susceptible to root rot, but Sasanqua Camellias are resistant to the disease. Root rot is difficult to control. A fungicide applied according to the manufacturer's directions may prevent root rot, but will not cure it.