The hibiscus is one of the easiest flowering houseplants to grow. With enough light and proper care, they are capable of growing and producing flowers all year round with the greatest profusion during the summer months. Be sure to place you hibiscus in a location that gets as much direct sun as possible.
For best results, put it outside when nighttime temperatures remain above 55 degrees. If your hibiscus has been inside for the winter, don’t move it into full sun right away. Give it just morning sun for a week or so before moving it into the all day sun it prefers. This will allow it to acclimate to the brighter light and avoid sun-scald and shock. Hibiscus are heavy drinkers during this active period, so be sure to keep the soil moist (not wet) to the touch. If the container has a saucer, make sure there is never water standing in the saucer. Drain the water from the saucer after watering or after rain. This will avoid drowning the roots. During its stay outside in full sun, feed your hibiscus a high phosphorus, soluble plant food with every fourth or fifth watering (about every two weeks). This, and the sun, will provide the energy needed for the non-stop flowering that hibiscus are famous for.
Hibiscus are attractive to insects, so spray every ten days with a good houseplant insecticide. Systemic insecticide added to the soil will control insects for up to sixty days. As the days shorten in August, start to feed at half strength. When nighttime temperatures dip below 55 degrees, you should bring it inside for the night. Bring it outside in the morning as long as the days are hot. During late September it will be time to bring your Hibiscus in for the winter. Prune off 25% of the foliage to help it adjust to the lower light inside. Stop feeding at this time. As the days get longer during March, start light feedings to prepare for the move outside in June.