Treating Aphids on Gardenia Bonsai with Neem or Alcohol

Black specs on gardenia leaf undersides that rub off are aphids—not mites. The sticky "flakes" on top surfaces are honeydew (aphid excrement).

Treatment Options

1. Neem oil: Follow label directions; apply weekly for 4–5 weeks
2. Rubbing alcohol spray: Straight alcohol in spray bottle; same schedule

Persistence Is Critical

Spray twice weekly for 2 weeks, then weekly for 3 more weeks to kill hatching eggs. Inspect regularly afterward. Aphids target stressed plants—check watering, light, and humidity to prevent recurrence.