The rose mallow, scientifically Hibiscus moscheutos, is perennial flowering plant used in landscapes and garden settings. The plant is sometimes called the swamp mallow for its preference for wet areas. This often used to advantage by gardeners with areas too wet for other landscape plants. The rose mallow does require some care each year.
The above ground vegetation of the rose mallow dies off each year after the frost. This plant can be trimmed back by clipping the stems 1 to 2 inches above ground level after the frost in the fall or in the spring before growth starts. Clipping in the fall gives the winter garden a cleaner look with less standing residue. Add the cut stems to a compost pile.
One reason to leave the rose mallow stems to spring might be to remind the gardener where the plants are. The mallow often gets off to a slow start in the spring and some gardeners may begin to doubt its location or even survival. Once it does break dormancy, it grows rapidly.
Rose mallow can reach a height of about 8 feet, although 4 feet is more common under most conditions. This is all new growth each spring. Flowers begin blooming in mid to late summer and can continue to the frost in the fall.
Grow new rose mallow plants from seeds allowing up to four weeks for germination if soil temperatures are at least 21.1 degrees C. It may take the first year to establish itself with blooms occurring during the second growing season. Established rose mallow plants can be lifted and divided in the spring of the year before they break dormancy.