If you are looking to add a tropical feel to your landscape or a late summer blooming plant, consider adding a hardy hibiscus.
The hardy hibiscus (hibiscus moscheutos) differs from the tropical hibiscus, (rosa sinensis) which is grown in warmer, more tropical climates like southern Florida or Hawaii. The tropical variety is not likely to survive cold winters unless potted and placed indoors for the winter, while the hardy hibiscus can survive winters in zone 4. These hardy plants are known to produce blooms that can vary from four inches up to a giant 13-inch dinner plate-sized diameter and can be found in reds, pinks and white flowers.
The hardy hibiscus is also known as "Rose mallow" or swamp mallow and is native to North American swamps. These plants did not get much attention from hybridist until a few years ago when several noted hybridist began developing various strains. Today, there are more colors and variety to choose from.
Swamp mallow plants will come up religiously every year and with proper care, bloom late in the fall till the first frost. If seed pods are kept picked off, your plant will continue producing multiple blooms later into the much cooler fall weather until the first frost.
Hardy hibiscus require much less care than the tropical variety. Once established, they will grow under a variety of conditions and are friendly to most soil. You can grow the shorter versions (3 ft.) in water up to six inches deep. This makes them perfect for low lying areas that collect water or a water garden. Rose mallow are not as likely to attract pests as the tropical version, and require no pruning. And, once established you will have fabulous blooms from mid-summer until the first frost.
Winterizing hardy hibiscus is simple. Wait until the first frost and cut the base of the plant. These bloomers need a period of dormancy to survive. Protect with 6-12 inches of mulch for the winter to protect their root system. In the spring, after the danger of frost has past simply rake the mulch off of the plant.
The most important thing to note about these tropical looking beauties is they are late to leaf out in the spring. It is important to give these plants plenty of time to leaf out before digging the plant up because you think it didn't survive the winter.
Anne Lenox Barlow has had experience in the agricultural field as a horticulture educator with Cornell Cooperative Extension in Clinton County. She can be reached by e-mail at firstname.lastname@example.org.