What is eating my bee balm?
When did you notice the whitefly population increase? Are all your plants affected?
Keep the plants appropriately watered. Do not over fertilize the plants, white fly populations increase when high nitrogen fertilizers are used, because of the soft tender growth high nitrogen fertilizer stimulates. Prune plants as needed to encourage bushier form.
The best program to control whitefly is to prevent the build-up of whitefly populations early in the season. Remove infested leaves and dispose of them in the trash. Hose flies off the underside of the leaves. Sticky yellow traps will trap adults, but nymphal stages and eggs remain on the undersides of the leaves, so the traps are more of an indication of the infestation level than a control method. Avoid insecticides, their use will backfire when they destroy the insects preying on white flies.