Tropical hibiscus (Hibiscus rosa-sinensis) is a flowering shrub cold hardy in USDA planting zones 8 through 10. For those of us in the chillier USDA planting zones, growing hibiscus indoors is must from fall into late spring though the potted shrub can be placed outdoors during the summer. Hibiscus can grow 10 to 15 feet tall and 5 to 8 feet wide. The shrub can be pruned to look like a tree. The red bloom pictured is ‘Rebellious Spirit’ and the yellow bloom is ‘Misfire.’
In spring, summer or fall, plant hibiscus outdoors in USDA zones 8 and further south. Choose a well-drained location in full sun. Dig the hole as deep as the root ball and twice as wide as the root ball. Digging the hole wider than the root ball loosens the soil making it easier for the shrub to spread its roots. Place the root ball in the hole. The top of the root ball should be level with the surrounding ground. Return soil to the hole around the root ball, filling the hole about half way. Water around the root ball, which will force out air and compress the soil. Finish backfilling the hole and water again. If planting more than one hibiscus, set them 3 to 6 feet apart.
Prune hibiscus as needed to maintain a desired shape or size. Spent blooms can be snipped off the shrub to improve appearance. Pruning is especially helpful for potted hibiscus to retain a size easy to relocate indoors. If your potted hibiscus becomes wider than the doorway, wrap a bed sheet around the branches to gently tug the branches in.