yellow hibiscus has white powder
The buds on my hibiscus has what looks like a white powder all over them. What is it and what can I do to control it?
This is Aphids.
I see some yellowing to the leaves also. This could indicate some watering issues.
Treat with Neem Oil, as this works as both an insecticide and fungicide.
Do this weekly until the pests are gone and as a preventative.
Here are a few links for you.