Question
My hanging baskets were blooming beautifully, until the middle of August, when they all at the same time quite blooming.  They are mostly varieties of petunias.  Something is destroying the leaves and the buds before they can bloom.  They were all in different locations of my yard and patio.  I notice what I call tiny black grains the consistency of salt on the flowers and leaves.  I have used an organic insect soap spray which has not helped.  Some are in pots on the ground with other flowers.  The geraniums have not been killed yet but are not as healthy as usual.  Is the insect in the soil and was it there when I planted the flowers and now just hatching?  What can I use to restore the flowering?  Thank You

Answer
Elizabeth,
Sorry for the delay in answering this - I just got back from being away.  Usually small black grains as you describe are the poop of larvae or caterpillars. The best control for these is any product with Spinosad as the active ingredient. This is an organic treatment, but you should spray in the evening when the bees aren't on the plants as the product when wet is bad for bees. Once dried it is fine for bees and everything else.  Spinosad is effective on a wider range of larvae than Bt, but it is a similar product.

Soap spray is fine for small insects such as whitefly and aphids, but larvae and caterpillars aren't effected by it.

Who knows where these things come from?  I doubt from the soil, however, because usually larvae hatch from eggs laid on the plant itself.  The good news is that Spinosad is extremely effective. It's not unusual for one plant to be eaten but not another type: insects (and diseases) are usually pretty host-specific: they eat one species of plant but not another.

To restore flowering of petunias the best thing is to do is to clip back about half of the stems by half (snip them off with scissors randomly around the plant) and water well, then fertilize with a liquid fertilizer.  The pruning will stimulate new growth, and the flowers on petunias are always produced at the end of the stems.

I hope this helps,
C.L.