Hibiscus Stem Issue: Powdery Mildew vs. Scale Insects

Hibiscus stems have a white, cottony/snowy growth. Owner asks for identification and treatment.

Two Likely Culprits

Treatment for Each

If Scale (Insect):

• Bayer Advanced Tree & Shrub Insecticide (imidacloprid) as soil drench.
• Systemic action kills bugs in ~1 week; protects up to 1 year.

If Powdery Mildew (Fungus):

• Homemade spray: 1 tbsp baking soda + 1 tbsp light oil (e.g., canola) per gallon water.
• Shake well; spray to runoff.
• Repeat every 4–5 days for 3 treatments.
• Monitor; retreat if mildew returns.

Identify correctly before treating.