| The white stuff is probably an infestation of mealybugs. They have cottony looking fluffs to protect them from predators and from some pesticide sprays. If your hibiscus is harboring a large population it might be easier to prune it back far enough to remove the pests. Some pesticides can control them but repeat sprays are necessary to get every last one. Check the pesticide labels to make sure they are safe to use on hibiscus against mealybugs. |
