Flamboyant hibiscus

Rose mallow forms amazing backdrop during the late summer
By: 
Rob Zimmer
Columnist

One of the more stunning and flamboyant blooming shrubs now comes into bloom as summer begins to slide into autumn and the days begin to shorten. Hardy hibiscus, also known as rose mallow, features blooms that may reach 6-10 inches across in some selections, making it a prized addition to the summer garden.

Reaching 5-6 feet in height at full maturity, these shrubs provide a breathtaking display during late summer, where they form a beautiful backdrop or create an impressive specimen plant for long-term enjoyment.

Once they begin to bloom, these shrubs can bloom for several weeks, featuring dozens upon dozens of large buds that unfurl into massive, crêpe paper blooms.

Most of the hardy hibiscus for our area bloom in shades of pink, red or white, though there are other varieties in pale yellow, lavender and purple.

Do not confuse these shrubs with the tropical hibiscus shrubs often sold in garden centers that are not hardy in our area and feature tropical colored blooms in red, yellow, orange and other bright, tropical colors.

Also known as rose mallow, a native shrub to the wetlands of Wisconsin, these hybrid hardy hibiscus have been bred to display some of the biggest blooms found in the garden during any time of the year. Some may exceed 8 or 10 inches across when the shrub has matured after 3-5 years in the garden.

A word of caution to gardeners who grow this plant: these shrubs are notoriously late in coming up in the spring, often, not emerging above the soil until around June 1. Many gardeners have assumed the shrubs did that return when out in the garden in April and May, and simply dug them up while they were still dormant. Allow plenty of time for this shrub to naturally emerge in late spring or early summer. Once the new growth appears, the stems and canes grow rapidly, forming buds in late July and August.

Even when not in bloom, hardy hibiscus makes an attractive and statuesque display plant in the garden. Many feature colorful foliage in rich purple or deep green. Some are rounded and heart shaped in leaf, while others are finally cut, almost like a Japanese maple.

Many popular varieties of hardy hibiscus are sold. Some feature candy cane colored blossoms in patterns of red and white. Others feature a bull’s eye bloom with a dark eye zone surrounded by a lighter or swirled pattern among the outer pedals. Others are solid colored in beautiful pastel pink, scarlet red, wine and rose.

Most varieties of hardy hibiscus grow best and reach their best proportions in full sun. Many are also adapted to part shade. Be sure to read the specific plant tag for each variety to determine placement in the garden.

Find Rob Zimmer on Facebook at www.facebook.com/RobZimmerOutdoors. Listen to “Outdoors with Rob Zimmer” from 4-5 p.m. Fridays and 7-8 a.m. Saturdays on WHBY.

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