Gardenia, white bugs and black residue on leaves

Apr 12, 2004 3 Replies

We have an outdoor gardenia that has these little white bugs, trapizodial in shape all over the leaves. The black residue will come off if you scrape it . The new growth doesn't have the buga or the residue. he residue comes off in pieces, lake paint that is no longer adhering to the wood. Any help would be appreciated



Ed Christie


Check the web for whitefly, especially giant whitefly. Bad news.

Sounds like scale. The black stuff is bug poop, also called sooty mold. All gardenias get it. Try some soapy water and garlic juice.

I agree it sounds like whitefly, which are particularly fond of gardenias. The black residue is sooty mold, a fungus which grows on the sticky substance excreted by the insects. It is not harmful on its own, although a heavy coating can interfer with photosynthesis. It washes off easily. Treat for the whitefly and the mold will take care of itself. Repeated applications of insecticidal soap are effective, as is neem oil.

pam - gardengal

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required