Answer: I don't know if the black spots are a fungal or bacterial disease or if they are a result of insect feeding so I'm not sure what to recommend. If the spots are actually within the leaf and not simply on the surface (scrape one to see if you can scrape it off) then your cleyera has a fungal or bacterial leaf spot. To control, remove the infected leaves when the plant is dry, either individually if only a few are affected, or by pruning the plant if the infection is widespread. Leaves that collect around the base of the plant should be raked up and disposed of. Avoid overhead irrigation if possible; water should be directed at soil level rather than on the foliage itself. If all else fails, you can spray with a fungicide. If you can scrape the black spots off, they are sooty mold, the residue caused by insect feeding. Insecticidal soap is effective against aphids, mealybugs and other sucking insects. Repeat applications may be required.
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