What Kind of Fungicide Can I Use for Camellia?

Petal Blight

• A common camellia fungus, petal blight affects the flowers but not the leaves, stems or roots of the plant. Brown spots on the flowers enlarge during warm weather as the fungus kills tissue. Often, gray, fuzzy mold appears at the spot where the flower attaches to the stem. The fungus survives over winter at the base of the flower and it spreads on the wind.
  Remove infected flowers from the plant and the ground and dispose of them in the garbage. Spray the plant, and any other camellias nearby, with an organic fungicide containing copper or a synthetic fungicide containing Captan. Camellia sasanquas, while susceptible to the fungus, don’t show symptoms because they bloom earlier than other camellias.

Canker

• Leaves on plants affected by canker fungus suddenly turn yellow and wilt and branch tips die. Gray blotches on the bark and stems turn into sunken cankers, eventually killing the stems and trunk above them. Most symptoms emerge during hot, dry weather. Keeping camellias healthy with proper planting in acidic soil, fertilizing regularly and being careful not to cause any wounds in the bark help prevent canker. Prune out diseased plant parts, wiping your pruners between cuts with a solution of one part bleach to nine parts water. Spray an organic fungicide containing copper salts of fatty acids or a synthetic fungicide containing thiophanate-methyl during periods of natural leaf drop or after pruning to protect scars.

Root Rot

• The initial symptoms of root rot fungus are yellowing leaves over the entire plant, followed by wilting. The root system lacks delicate feeder roots. If you dig up the plant, you won’t see good, healthy white roots. Japanese camellias are susceptible to root rot, while sasanqua camellias are not. Prevent root rot by planting in well-draining soil. Fungicides are worthwhile only as prevention but won’t cure an infected plant. Spray each spring with an organic fungicide containing copper or a synthetic fungicide containing etridiazole.

Leaf Gall

• More common in sasanqua camellias, fungal leaf galls appear in spring on new growth. New leaves and stems thicken and turn from green to white or pink. The galls form on the undersides of the leaves and burst to release a mass of white spores. The disease is rarely fatal to the plant and can be controlled by removing infected leaves and shoots before the galls burst. Wet, humid weather or overhead watering set up favorable conditions for the fungus. To help prevent leaf gall, begin spraying the plant at bud break with an organic fungicide containing copper or with a synthetic fungicide containing mancozeb and repeat according to label directions. Rake up fallen leaves and petals regularly and keep the area mulched.