How to rid large, old gardenia bushes of sooty mold. Moved into old home with well established yard on the marsh. Gardenias (near marsh) are heavily infested with scale & sooty mold. Have read numerous articles re: neem oil, washing, etc., but concerned bushes may be "too far gone." Bushes have not been treated, but continue to produce new growth. Ok to cut way back - similar to old azaleas? Open for all suggestions as would hate to lose them.
Gardenias / Sooty Mold
Certified GKH Gardening Expert
Neem Oil is organic and safe for people, pets and bees.
Treat the plant and then repeat weekly until you see improvement.
Pruning in late summer is fine for your plant. Waiting until the plant begins to improve from the fungus issue, will help reduce the stress when you prune.
Prune no more then 1/3 this summer.