Cottony Growth on Hibiscus: Woolly Aphids or Scale?

Cottony Growth on Hibiscus: Woolly Aphids or Scale?

White, cotton-like masses on hibiscus stalks near buds, accompanied by flower failure, are typically woolly aphids or cottony scale insects. Both produce waxy filaments for protection and excrete honeydew that can lead to sooty mold.

Diagnosis and Treatment

1. Collect a sample of the cottony material and take it to your local nursery or county Extension office for positive identification.
2. Woolly aphids: treat with insecticidal soap, neem oil, or systemic imidacloprid.
3. Scale: apply horticultural oil during crawler stage or use a systemic soil drench.
4. Natural predators (lady beetles, lacewings) often provide control if pesticides are avoided.

Accurate ID ensures the most effective, least toxic treatment.