Hibiscus – Granular Deposits on Leaves

Q: There are irregular shaped, granular deposits on front and back and upper stems of my miniature hibiscus leaves, grown in a sun room. They feel like fine sand. What is it and how to control?

A: UGA’s tropical plant expert Bodie Pennisi says it’s most likely a physiological problem called oedema. It occurs quite frequently on geraniums, sweet potato vine and even on poinsettias. The culprit is fluctuations in the environment; it is most commonly a greenhouse problem. High humidity is a primary cause.

Start checking the soil with your finger before watering. If it is damp, there is no need to add water. The deposits can be brushed off the leaves.

Hibiscus White Granular deposits