Camellia bushes are prized for their late fall to early spring flowers, when few other plants are blooming. The single or double flowers are shades of red, pink and white. The evergreen leaves of camellia bushes add structure to the winter garden and provide a backdrop for summer blooms. Camellia bushes grow in a various forms, from upright to spreading. Some varieties of camellia bushes grow 15 feet tall or more, but it is easy to keep the plants pruned to a smaller size because of their slow growth.
Camellia Flower Blight
The fungus Ciborinia camelliae causes camellia flower blight, also known as petal blight. Slimy brown spots appear on the petals, which eventually cover the whole bloom. The flowers fall off the bush, where the spores can remain dormant in the ground for up to four years. During humid warm conditions, the spores grow into small brownish-gray mushrooms. The mushrooms release new spores into the air, which can travel by wind as far as half a mile. Remove debris from around bushes and replace mulch each year to help prevent camellia flower blight. Apply a fungicidal spray to bushes and a fungicidal soil drench around bushes with a product approved for camellias. Follow the manufacturer's directions for rates of application.
The fungus Glomerella cingulata causes camellia dieback. Symptoms include sudden wilting of new growth and development of cankers on limbs and trunks of camellia bushes. Prune infected plant parts and apply a fungicide approved for camellia dieback according to the manufacturer's directions.
Leaf galls caused by Exobasidium camelliae are most common on Sasanqua camellias. In the spring when new growth appears, a few infected leaves will thicken and feel spongy. These leaves do not hurt the plant, but they are unsightly. Remove the leaves to prevent infection of the next year's growth. No other treatment exists for leaf galls on camellias. Several different fungi cause leaf spots on camellia bushes and usually cause little damage. Use a fungicidal spray approved for camellia leaf spots at the application rate recommended by the manufacturer.
Gray mold, also called Botrytis flower blight, is a gray powder on the petals of camellias, especially the stamens. Apply a fungicidal spray approved for gray mold on camellia bushes at the rate recommended by the manufacturer. Sooty mold is a black powder that grows on a sweet sticky substance called honeydew, which is secreted by aphids, whiteflies and scale insects. Wash sooty mold off with water. Use a pesticide for aphids, whiteflies and scale insects on camellia bushes according to the manufacturer's directions.
You can prevent most camellia bush diseases with proper planting and maintenance. Plant camellia bushes in partial shade or filtered shade in acidic soil (pH 5.0 to 6.5). Allow adequate space between plants based on the mature size of each variety to improve air circulation. Remove debris from around bushes regularly and replace mulch yearly to prevent the fungal diseases from returning.