Tropical hibiscus flowers are one of the enduring symbols of the tropics. These much-beloved, large and showy flowers can be grown inside in temperate zones, but it's not an easy task. The trick with success is twofold: managing the deadly winter, and fending off hungry insects. If you can fall into a rhythm, it's possible to keep a hibiscus plant thriving for a decade or more, with blooms in the summer. Remember, though, that the blooms will likely never be as large as those in South Florida, California or Hawaii, where hibiscus blooms can be as large as dinner plates.
Place outside in the summer, gradually acclimating to more light. In the winter, give as much direct light as possible.
Water freely in the summer, but excellent drainage is a must. Never let the mix become soggy. In the winter, let dry almost completely before watering again.
Even a few nights below 50ºF will kill a hibiscus. Move them inside when the temperature is consistently 55ºF. They prefer between 55ºF and 70ºF.
Use a well-drained potting mix
Feed in the early summer with a slow-release fertilizer or weekly with a liquid, blooming fertilizer.
Hibiscus can be propagated with soft-stem cuttings in late spring, when the plant begins to grow again. Use rooting hormone and shelter the cutting from direct sun until it begins to grow.
Repot as necessary, yearly or biannually. Hibiscus will grow into trees in their native habitats, but this may be unwieldy in a home setting. There's also some benefit to keeping the hibiscus in a relatively smaller pot, as it will make for easier pruning and moving.
There are literally dozens of hibiscus varieties introduced every year. They flower in red, pink, orange, yellow, and white. There are single and double versions available. Choose freely among the hybrids.
Hibiscus should be moved outside in the summer, then back inside during the winter. Tips for a successful transition include:
- Trim the plant hard before moving it inside for the winter. It will go into near dormancy until late winter.
- After you trim it, but before you bring it in, treat it thoroughly for insects. Neem oil and liquid detergent work well, or use a hose to blast off insects.
- Once inside, don't overwater, but provide as much humidity as possible, including daily mistings. Don't expose to blowing air from vents.
- When the weather warms to above 50ºF at night, move it back outside and acclimate slowly.