Hardy hibiscus (Hibiscus moscheutos), also known as rose mallows, evoke visions of the tropics in places where winter temperatures often flirt with minus 30 degrees Fahrenheit. They produce dazzling displays of five-petaled, crinkled trumpet booms as large as 10 inches across. Fleming’s Flower Fields of Lincoln, Nebraska, patented “Plum Crazy” (Hibiscus x moscheutos “Plum Crazy” PP11854) in 2001. A standout, compact cultivar, this hibiscus covers its 3-foot form with hummingbird-attracting flowers from midsummer well into autumn.
“Plum Crazy” Heritage
Fleming’s flower growers produced the first “Plum Crazy” hybrid in 1970. The business crossed an unnamed scarlet rose mallow (H. coccineus) and hardy hibiscus (H. moscheutos) hybrid with self-pollinated seedlings of “Dahliatown Orchid” (H. moscheutos “Dahliatown Orchid), an unpatented cultivar in the Dahliatown Nursery in Middleborough, Massachusetts. “Plum Crazy’s” strikingly veined petals trace to “Dahliatown Orchid.” After almost three decades of testing the plant’s traits for stability, Flemings patented “Plum Crazy” in 2001.
Plant Attributes
Exactly what “Plum Crazy’s” blooms lack in operation, they compensate for with numbers and attitude. Tightly furled, columnar buds open into 10-inch, plum-colored trumpet blooms adorned with purple veining. Deep-purple throats crowded with red-and-yellow stamens add influence. Individual flowers last only a day, but in the peak of bloom, buds and blossoms nearly conceal the foliage. Prior to its buds emerge and once they fade, “Plum Crazy” gets attention for its dense, three-lobed purple leaves. All the visual drama unfolds on a shrub just 3- to 4- ft high with a two- to 3-foot spread.
Growing Conditions
The “Plum Crazy” hibiscus hybrid rises across U.S. Department of Agriculture plant hardiness zones 4 through 11. Planting the tree in which it receives eight hours of direct daily sunlight promotes the heaviest flowering while decreasing its risk of disease. It performs best in a well-drained, wind-protected place with organically rich, moist and a soil pH between 6.8 and 7.7.
Watering
Even more drought-tolerant than species hardy hibiscus plants, “Plum Crazy” prefers to dry out slightly between waterings. After wetting the ground slowly and deeply using a drip system or soaker hose, wait until the soil’s top 4 to 6 inches are dry to the touch before watering again. Moisture evaporates more quickly during hot summer weather. Applying a 2-inch layer of organic mulch, such as wood chips, around the plant slows the evaporation.
Fertilizing
Feeding actively growing “Plum Crazy” monthly with an all-purpose, micronutrient enriched 20-20-20 fertilizer promotes vigorous foliage growth and abundant flowering. Use the fertilizer at the label’s suggested rate for the size of the tree.
Grooming
“Plum Crazy’s” modest dressing requirements comprise deadheading its flowers as they fade and cutting any broken or crossing branches. Cut all of its stems back to within 4 inches of the ground once they die back in late autumn.
Problems
Bred for disease and pest resistance, “Plum Crazy” can develop problems from ecological aspects. Wind scorch sometimes affects blooms on shrubs in exposed locations. Those in too much shade often have sparse flowers and leaves, and lose their tidy habit as they stretch toward sunlight.