Answer: In my experience the angel wing begonias will not bloom unless they are in enough bright light, it should be very bright but still indirect. They also need regular fertilizaton with a slow release or water soluble fertilizer such as 10-10-10 plus minors. Feed from spring through fall when actively growing, follow the label directions for how much to use. Sometimes older plants lose vigor. You could try rooting some tip cuttings to start new plants and see if that helps. Here are instructions on how to do that.
Good luck with your begonias!
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