How to Grow Hibiscus

Hardy hibiscus can be started from seed or plants can be purchased from your local garden center. To get a jump-start on the growing season, the National Garden Bureau recommends starting seeds indoors 6 to 12 weeks before the last frost date in your area. Soak the seeds overnight and then sow ½ inch deep into well-draining soil. Keep soil moist. After four to five weeks, transplant to larger pots. After the last frost date, begin hardening off the transplants by transferring outdoors to a shady spot for a few hours each day. When they have become acclimated to the outdoors, plant them in your landscape or position them on your patio. Giving them a chance to become acclimated helps prevent bud loss and minimize foliage loss.

 If growing in a container, use a large container with drainage holes and a well-drained potting mix. Even though this plant likes water, its roots may rot in the container if it doesn’t drain adequately. 

Plant hardy hibiscus in full sun with plenty of room to allow for good air circulation. The plant is tolerant of a wide range of soils if they do not dry out. It does best in slightly acidic, well-draining soil that has been amended with plenty of organic matter. If in Northern climates, plant in full sun in your landscape. If you live in the South, Hibiscus may benefit with some slight shade, particularly from the hot afternoon soon.

Plant after the danger of frost has passed. Dig a hole that is double the size of the container. The crown of the plant should be at or slightly above the soil surface. Press the loose dirt around the plant and water in. Add more soil if the base of the plant shows after watering.

Keep the soil moist but not saturated. Do not allow it to dry out. Drought conditions stress the plant and may reduce its growth and blooms.

Hardy hibiscus, particularly the newer, more compact varieties, require little pruning during the growing season. If you have an older variety that grows quite tall, it can be cut back in the early spring. The Missouri Botanical Garden advises pinching back growing tips when they reach 8 inches and again at 12 inches if bushy plants are desired. If you miss this step, when the plant is 2 to 3 feet tall, cut it back by about one-third to one-half. This helps the plant have a more compact and attractive appearance. For Rose of Sharon (Hibiscus syriacus), prune it in the winter when it is dormant.

In the late fall or winter, leave the woody stems of hardy hibiscus standing until spring, then prune them back to 4 to 6 inches. New growth will emerge from the ground. In locations with harsh winters, mulch around and over the plant may help it survive. 

Fertilizing

• Hibiscus plants are heavy feeders. Fertilize regularly throughout the growing season. Both organic and inorganic fertilizer for flowers and shrubs is available in liquid or granular formulas, and some are labeled specifically for Hibiscus. Follow label directions.
• For indoor plants, use one-half strength formulation about every month or so during the growing season, and less frequently in winter.

Controlling Pests, Diseases, and Other Problems

•  Aphids, thrips, and spider mites sometimes bother this plant. Horticultural oil or insecticidal soap can be used; follow label directions. 

• Hardy hibiscus is one of the last perennials to emerge in the spring, sometimes as late as mid-June, so don’t get too concerned when it is slow to make its appearance. When the new shoots finally emerge, they take off and grow quickly.
• Hibiscus are water-tolerant and may be a good option for low, damp areas that stay moist, for areas near water features, or for rain gardens. They are dramatic and can be a beautiful accent plant, or to add interest to a perennial garden. When several are planted, they can serve as a hedge.