How to overwinter tropical hibiscus in pots?
I have several tropical hibiscus plants in pots that I bought new last spring. In previous winters where I've tried overwintering them in my garage, I can't seem to get them to recover in the spring soon enough to bloom before late summer. When I bring them back outside after the last frost, they start to grow new foliage well, but it has always taken 3 months or more to start blooming again. If I want blooms all summer, I have to buy new plants. What is the secret to overwintering them and then getting them kickstarted in spring to bloom early?
My garage is attached to my house with a room above it, so it stays reasonably warm--probably never lower than 55-60 degrees on the coldest days/nights of winter. And there are two windows on one side and one window on another....not a lot of light, but not dark for sure.
What should I do as far as pruning, fertilizing, watering, or anything else that may be important to getting them to recover and bloom quickly in the spring? I put them into my garage about 2 weeks ago, and can usually take them back out in early April.