Question
I just planted hibiscus plants and cannot get rid of the black spots (some kind of small bugs), aphids, etc. around the tips. I've tried insecticidal soap and rose insect sprays to no avail. I use them every other day! Suggestions? I am in southern california.

Answer
Chris,

If they are aphids, then they should have been controled by the spraying. Are you sure they are bugs? It is entirely possible that the black spots that you see are caused by the disease, leafspot.

Since leafspot cannot be controled when the spots are present, there is nothing to do for the shrub now except for fertilizing it well and scheduling a fungicide treatment for early next year.

If it is aphids, or some other insect, you could try spraying the shrub with either carbaryl or any ortho general insecticide.

Good luck.
Ed Gulliksen