Mealybugs on Hibiscus: Not Fungus, Treat with Horticultural Oil

A UK gardener sees feathery white clumps on hibiscus stems, thinking it's fungus. It's actually mealybugs—soft-bodied scale insects covered in white wax.

Identification Test

Touch a cotton swab dipped in alcohol to the white fluff—it dissolves instantly, confirming mealybugs.

Treatment

• Small plants: Dab each with alcohol on a swab (time-consuming).
• Best method: Spray entire plant with lightweight horticultural oil (e.g., SunSpray). Cover tops and bottoms of leaves, stems, and leaf nodes. Repeat weekly for 2–3 applications.

Oil smothers all life stages. Avoid spraying in direct sun or when bees are active.