Question
I believe you answered my question about pruning roses in Hawaii - thank you. Now I need to know how to get rid of the moldy white stuff on the stems of my roses bushes. What is the best product for my area -Maui, Hi?

Answer
What you are describing is a mould which does very well when the air is humid. Certain colours are more prone to it such as reds and oranges but it will effect all colours. there are a couple of things you can do. If you are an organic gardener then you can mix up 1 tablespoon baking soda with 1 quart of water and spray daily until the mould has gone. If the mould is thick then any fungicide for roses will do the job for you. If you can get a product called Funginex then that is the best one. However many of these products are being taken off the market under the pesticide laws.
Keep an eye open for the bushes that are the worst as they will be the first to get it when conditions are right for moulds. Hope this helps.