The hardy hibiscus
Hardy hibiscus (Hibicius moscheutos) is commonly called rose mallow. With large tropical flowers, it can be a showstopper in your landscape.
My pink hibiscus is in the middle of a flower bed with a large hydrangea behind it, surrounded with layers of morning lights grasses, an arbor with sweet autumn clematis in front of it and daisies to the edge. This combination makes a soft color palette that lends itself to being a “white” garden as the large pink flowers combined with the white of the hydrangea, sweet autumn clematis and daisies shine in low light conditions.
This plant grows from 2 to 12 feet tall with large 6- to 12 -inch wide flowers in white, pink, red or bicolored that bloom from midsummer through fall. Many newer compact hybrids are easier to fit into space-challenged gardens. One of the smallest is the Luna series that will look great around a patio or even planted in containers. When you plant your hibiscus, choose doing so in the spring over fall. This gives your plant time to form roots instead of spending the energy trying to bloom. Adding some extra mulch for winter protection will help survival if planted in fall. The plant is completely hardy once established.
The flowering is similar with that of daylilies as the individual flowers only last one day. Then they get mushy, but they are covered with enough buds to give you flowers for several weeks. If you deadhead flowers before they reach this stage, it will help prolong blooming and plant appearance. The seedheads are attractive and can be left on the plant to add interest throughout the winter. Fall or spring, cut back the stems to 4 or 5 inches high as they regrow from the base and are often late to leaf out.
If you want more plants to add to your landscape or to share with friends, spring is the best time to divide hardy hibiscus. As with planting a new one, this also applies to planting new divisions to allow root growth to occur. Lift out a clump and split the root ball with a sharp spade or knife. This would be an impossible task once it gets some growth as mine takes on a treelike stance once it gets going. You can control the height by cutting the plant back by one-third in early summer to maintain a more compact size. If you already have a large cultivar you want to “tame” this would be an option but would be easier to choose a compact hybrid for a new planting.
Come spring, be patient with this plant. It is slow to emerge. Don’t assume it is dead and dig it up. Just wait. It is worth it.
To learn more about these beauties, go to http://go.osu.edu/hardyhibiscus.