When I acquired my first hibiscus, the man in Paynes  Nursery in Towcester told me it is known as "Gardener's nightmare" because you think it will never flower, then it bursts into leaf and flower just as you are thinking of digging it up.  I now have three - rose pink, pale violet and deep inky blue - and all flower beautifully every year, in poor soil, totally neglected and crowded by other plants.  So treat 'em mean, Steve.