Hardy Hibiscus – Hibiscus moscheutos
Hibiscus moscheutos has the tropical appeal of other Hibiscus species but is surprisingly well-adapted to survive in cold climates. For this reason it is commonly known as hardy hibiscus. Another common name, swamp rose mallow, refers to the wet environments where it is found growing naturally. Its native range spans from Texas eastward to the Atlantic coast and then north into Ontario, Canada. It is a robust, woody perennial in the mallow family (Malvaceae) that reaches up to 7 feet tall and 4 feet wide. Its flowers can be the size of a dinner plate, and its large overlapping petals come in a range of colors from white to pink to deep red, often with a maroon or crimson center. The pistil and stamens form a central column that is prominently displayed. Each flower only lasts a day or two, but new flowers open each day throughout the bloom period which runs from July to September.
Hardy hibiscus requires regular watering during summer months and prefers soils rich in organic matter. It is best grown in full sun in an area with good air circulation. Spent flowers can be removed to keep the plant looking nice. In late fall, the plants should be cut down to about 3-4 inches.
There are dozens of commercially available cultivars and hybrids of Hibiscus moscheutos. There are also a handful of other Hibiscus species that are considered cold hardy. This SFGate article is a great introduction to the different species of hardy hibiscus.
Visit Idaho Botanical Garden and you will find hardy hibiscus currently blooming in the Welcome Bed, the Sculpture Bed above the Plaza, and the English Garden. Hibiscus syriacus, commonly known as rose of Sharon, is another species of hardy hibiscus that can be found blooming at the edge of the Children’s Adventure Garden on the pathway below the tree house.