A large evergreen shrub native to mild regions of Japan, the sasanqua (Camellia sasanqua) grows beautifully in USDA winter hardiness zones 7 through 9. Tolerating considerable amounts of direct sunlight, unlike common/Japanese camellias, a sasanqua bears its fragrant flowers, which have up to eight petals, in the autumn to early winter months. Modern hybrids and selections allow gardeners to grow sasanqua plants that bear white, pink or rose-red blossoms.
Caused by the fungus Exobasidium camelliae, leaf gall typically manifests in spring, when new leaves emerge. Although the sasanqua plants are rarely harmed, leaf gall is unattractive. The infected leaves are abnormally large and colored a sickly light green to nearly white. On leaf undersides are the fungal galls that rupture to release whitish spores. Humid, moist, overly shady garden conditions favor leaf gall problems.
Once a sasanqua battles the canker and dieback, caused by a fungus named Glomerella cingulata, the situation is dire, if not simply bleak. This disease causes leaves to quickly turn sickly yellow, and then stem tips wither. Gray blotches appear on the shrub's bark, and soon sunken areas (the canker) appear in the bark and will encircle the trunk or branches. Areas below (closer the root system) the canker areas remain more healthy looking, while tissues above the canker fully yellow and shrivel. In hot, dry weather, the leaf yellowing and stem shriveling symptoms are exacerbated.
Fast-acting, the fungus Ciborinia camelliae cause only flower petals to brown. According to Clemson University, the flower entirely browns and drops off within one to two days. This fungus lives in the soil and is regarded as a serious disease, as it can fully void an ornamental sasanqua shrub of all its desirable flowers annually. While unusually cold weather can cause petal edges to brown, a key identifying feature of flower blight is that the brown discoloration penetrates quickly to the central core of the blossom.
While other species of camellia are susceptible to the root rot caused by the fungus Phytophthora cinnamomi, sasanquas are immune. Unfortunately, another fungus species, Cylindrocladium crotalariae, does cause root rot on sasanqua plants, especially when the plants are young or cuttings are made for propagation. The American Camellia Society mentions that established, mature sasanquas are typically not harmed by this soil-borne fungus.
Yellow Mottle Virus
There is no cure for yellow mottle virus once a sasanqua is infected. Typically caused by poor sanitation by camellia growers when they propagate stem cuttings, this viral disease is identified by the yellow mottling and speckling that decorate the dark-green leaves. Flowers can have irregular white blotches. Clemson University recommends avoiding this virus in your garden by only purchasing sasanqua plants grown from reputable breeders/nurseries that guarantee virus-free plants or employ sterile propagation techniques.