Question
My knockout roses are showing signs of disease.  The leaves have holes and some are spotted with white dust.  I found caterpillars on the leaves.  I sprayed the leaves with Bayer Rose Insecticide.  The caterpillars are gone but the white dust is still there.  The roses are pink and red.  The pink roses are fading.  Any advice to get the Pink roses healthy again.

Answer
The white dust is called Mildew and 1 tabelspoon of baking soda in 1 quart of water sprayed daily until there are no signs should really help get rid of it. Using an organic type spray will do the job because the disease hasn't really become serious. If it does, then try a spray for mildew on roses but the home made spray should solve the problem for you.