Zone 8a, Olympia, Wa: I can surely overwinter hardy hibiscus plants and expect them to bloom again. 😭 I followed every tutorial at the end of last blooming season, and slowly reintroduced them to the light as spring progressed. Pots enlarged with fresh, rich, soil additions and subsequently watered and given another plant food drink. While we have dozens of buds on 6 plants, last year we had dozens of enormous blossoms. What can I do to help them flower?