All around town I see that the winter hardy members of the hibiscus are putting on their show. Their flower closely resembles that of the tropical hibiscus that is so popular in the tropics. It is the state flower of Hawaii.
The tall (up to 10’) woody shrub that we see blooming around the area right now is althea also called Rose of Sharon. It seems that althea is gaining in popularity lately. I greatly admire the single flowering varieties that I’m starting to see more of. These single flowering altheas weren’t widely available when I planted my hedge 10 years ago or I would have surely opted for one of those. Rose of Sharon is available in a wide range of colors but tend toward the reds and lavenders. There are even varieties that have a bi-colored flower and there’s a nice white that I’ve seen as well. The flowers are a bit smaller than those of the tropical hibiscus but you can see the resemblance.
While the althea is a woody shrub, there’s another hardy hibiscus, the mallow hibiscus that is perennial in nature (it dies to the ground in winter). Like althea or Rose of Sharon, the mallow hibiscus is a relative of the tropical hibiscus although the flowers are much larger. The showy mallow hibiscus will grow from the ground to a height of 4’ to 6’ during each growing season. Mallow hibiscus flowers range in color from white to deep purple and encompass every shade of pink in between. As if this weren’t enough, the flowers can be as large as a dinner plate! I know you’ve seen these around town since they are in flower right now. A lot of folks don’t realize that this plant is hardy in our area and will easily survive over winter to return larger and showier each year. Each of the giant flowers that a mallow hibiscus produces will only remain open for one day. Fortunately, they produce plenty of buds so the show goes on for at least a couple of weeks and even longer for a well-established clump. You can see how large Mallow Hibiscus flowers are by using my face for comparison...this is the largest flower we can grow this far north...the tropics have nothing on us!
If you plant either of these northern members of the hibiscus family, you’ll need to be patient in spring. Neither the woody shrub althea nor the perennial mallow hibiscus will show any sign of life until spring is well under way. I usually see no sign of life from either in my yard until the lilacs are in bloom. That’s when the first leaves appear on my althea and the mallow hibiscus is just poking a shoot up from the soil. They are amazing plants and easily deserve a place in your garden.
Thanks for the read!
