Knowledgebase

Hibiscus leaf spot issue #923643

Asked January 14, 2026, 10:14 PM EST

Hi there! I’m trying to help my friend figure out what’s wrong with her hibiscus. It had been outside and brought inside for winter. It had aphids a little while back but they seem to be gone now. The leaves have been developing small black spots all over and dropping off. (Sorry for the picture quality with the grow light on.) Do any of you recognize what could be going on with this hibiscus or have any advice? Thank you so much for your time!

Multnomah County Oregon

Expert Response

Thank you for your question, Nadia.  Although OSU has no information on this species, UCal lists the diseases and pests of rose mallow here:  https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/hibiscus.html  The spots appear to be bacterial spots, but, under a microscope, virus patterns might be apparent.  The incidence of either of these is increased if the plant is outdoors (and aphids can carry viruses).  I suggest that you send leaf samples to the OSU Plant Clinic for examination:  https://bpp.oregonstate.edu/plant-clinic/submit-sample/how-submit-plant-materials

I hope they can help you and your plant!  Good luck!
An Ask Extension Expert Replied January 15, 2026, 5:52 PM EST

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