Question: My rose-of-sharon drops almost all of its buds before they ever open. Do I need to water it better, or is it some kind of pest problem?
Answer: That’s a common problem for all of the hibiscus clan, tropical and hardy alike. They seem to over-produce flower buds, only to get to the point of having to support all that reproductive growth just as it’s getting hotter and drier. Their prevalent reaction is to abort half or more of their buds just before, or just as, they begin to show color. Check the buds for signs of thrips (small, nearly microscopic insects that sometimes will be inside the buds). Most times, you won’t find them, so plan on mulching your plants and keeping them uniformly moist during the heat. Avoid high-nitrogen fertilizers around althaeas as they begin setting buds.