How to Grow and Care for Hardy Hibiscus

What is Hardy Hibiscus?

Hardy hibiscus (Hibiscus moscheutos) is a mid-summer blooming perennial with large, round flowers in shades of pink, red, or white.

Additionally, there are many common names for this hibiscus, including rose mallow, swamp rose mallow, perennial hibiscus, and marshmallow hibiscus.

Hardy hibiscus are in the mallow family (Malvaceae) along with hollyhocks, cotton, and okra.

Hardy Hibiscus Flowers

This plant produces large, 6- to 8-inch blooms in mid-summer. Blooms can continue for up to 3 months.

• 5 flower petals overlap on each flower, similar to a pinwheel.
• Each flower lasts one to two days.
• The flowers are often referred to as “dinner plate” size.  However, they are the size of a salad plate.

Plant Size of Hardy Hibiscus

Surprisingly, the plants range in height from 2 to 8 feet and in width from 3 to 6 feet, depending on the cultivar.

Where to Grow Hardy Hibiscus

Chiefly, it can be grown in landscape beds with other perennials and shrubs.

Add hardy hibiscus to rain gardens since they are adapted to moist soil.

The compact cultivars can be planted in containers, allowing the large flowers to be appreciated up close.

Native Habitat and Range of Hardy Hibiscus

It is native to North America, ranging from Texas eastward to Florida, northward to New Jersey and westward to Ohio and Indiana.

How to Grow Hardy Hibiscus Successfully

USDA Hardiness Zones

• Hardy hibiscus can be planted in USDA planting zones 4 through 9.

Sunlight Requirements

• Plant in full sun. It can also be grown in afternoon shade.
• The number of flowers increases with more sun.

Soil Preparation

• Plant in soils that are moist to well-drained. Unquestionably, they are most often found growing in moist soil environments in nature.
• Many cultivars can be planted in pots with a quality potting soil.

Watering Tips

• Basically, water regularly until plants are established. Once established, water during periods of low rainfall.

Fertilizing Hardy Hibiscus

• Apply a 2-inch layer of compost annually
• If needed, fertilize with an all-purpose, slow-release fertilizer in late spring.

Pruning and Maintaining Hardy Hibiscus

• As the plants begin growing in spring, pinch the growing tips to make the plants bushier.
• Support tall stems with stakes. Stems with flowers can bend in a heavy rainstorm.
• Pick off spent flowers so the plant puts its energy into producing new flowers.
• Above all, leave the dormant stems in winter to house solitary native bees. In late winter, cut back the stems to 6 inches high.

How to Propagate Hardy Hibiscus

• Generally, many cultivars can be grown from seed, including the series Luna™, Honeymoon, and Disco Belle™.
• Mature plants can be divided.

Hardy Hibiscus Pests and Diseases

• Japanese beetles and sawfly caterpillars cause the most damage, eating so much of the leaves that they look skeletonized. Both can be picked off the plant by hand and submerged in soapy water.
• Aphids and whiteflies can also visit plants.

Source:  Clemson Extension, Clemson University

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