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   Get It Growing
 Home>News Archive>2013>May>Get It Growing>

Try althea for summer color

For Release On Or After 05/10/13

By Dan Gill
LSU AgCenter Horticulturist

Louisiana gardeners crave color in the landscape. When thinking about landscape color, we often tend to focus mostly on annual bedding plants. These plants are bred and selected to produce outstanding displays of color.

But flower gardens full of bedding plants are relatively high maintenance. Flower beds need to be properly watered, groomed and weeded to look good. And when plants in these beds finish at the end of their season, they must be removed and replaced with new plants.

We often overlook how much color we can get from low-maintenance woody plants. Whenever you’re selecting trees and shrubs, choosing those that bloom at various times of the year can help boost color in your landscape without a lot of work.

For instance, choose sasanquas and roses to bloom in fall; camellias to bloom in winter; Japanese magnolia, azaleas and spireas to bloom in spring; and crape myrtles, oleanders and vitex to bloom in summer.

See. It’s just that easy.

One of the best choices when doing this is a lovely summer-flowering large shrub or small tree called althea or rose of Sharon (Hibiscus syriacus). Notice this is a species of hibiscus. When you look at the flowers of althea, you can see the strong resemblance to other species of hibiscus. It’s closely related to the tropical hibiscus (Hibiscus rosa-sinensis), Confederate rose (Hibiscus mutabilis), and hardy hibiscus or mallow (Hibiscus moscheutos and hybrids).

Altheas have graced Southern gardens for many generations and are prized for their long season of bloom from May to late summer. Like many species of hibiscus, individual flowers only last a day or two. But it produces buds continuously through summer, keeping the display going for months.

The flowers are generally single, but you can find attractive double-flowered types as well. Flower size varies, but most are fairly large at around 4 inches wide. The color range is nice, including shades of white, pink, rosy red, violet and lavender blue – often with a contrasting deep red throat.

The foliage is attractive dark green and is shed in winter. Varieties with leaves variegated green and creamy white, such as Sugar Tip, add to the display.

Altheas are completely cold hardy throughout Louisiana. Like so many traditional Southern landscape plants, althea is native to the Far East. It is the national flower of South Korea.

Many fine varieties of althea are available to choose from these days, and new varieties continue to be released. But, the Louisiana Super Plants selection committee has singled out Aphrodite althea (Hibiscus syriacus Aphrodite) for special recognition. It has been named a Louisiana Super Plants selection for spring 2013.

Aphrodite althea

The Aphrodite althea belongs to a group of altheas introduced in the 1980s by the U.S. National Arboretum. Others in the group are Diana (white), Minerva (lavender with a red throat) and Helene (white with a red throat).

All of these althea varieties are sterile hybrids. Old-fashioned altheas are well known to set abundant seeds, which readily germinate. This could lead to unwanted seedlings in the landscape. Aphrodite and others in the group have been specially bred not to produce seeds. Not only does this eliminate unwanted seedlings, it allows the plants to bloom more and longer.

Aphrodite was chosen for its outstanding performance at the LSU AgCenter’s Hammond Research Station. Plants grow to be about 8 to 10 feet tall and about 6 feet wide and are densely clothed with attractive, dark green foliage.

The typical growth habit is shrubby and multi-stemmed with a vase shape spreading at the top. Aphrodite althea tends to be especially full and dense compared with other altheas. Planted 4 or 5 feet apart in a row, it makes an excellent screen.

But the growth habit can be versatile, depending on how it is pruned. By reducing the number of trunks and removing the lower branches, an althea can take on a more tree-like appearance. Yet its small size would allow its use close to patios or buildings.

The large, 5-inch, single flowers of Aphrodite althea are rosy pink with a dark red eye, and the petals of are richly ruffled. The flowers appear in great profusion beginning in May and into June, with intermittent flowers through late summer. When the Aphrodite altheas are in bloom at the Hammond Research Station, visitors are literally drawn to the planting by the sheer beauty of the flowers.

Altheas in general are known for their tolerance of a wide variety of growing conditions and ease of maintenance. And Aphrodite is no exception. Planted in sunny to partly sunny locations with good drainage, they will just about take care of themselves.

Louisiana Super Plants selections have been tested and evaluated by LSU AgCenter horticulturists and the landscape and garden industry in Louisiana. These plants have been found to be reliable and outstanding choices for Louisiana landscapes. Super Plants selections can be planted knowing that they have a proven track record growing in Louisiana’s unique climate.

For more information on Louisiana Super Plants and to find a participating nursery near you where you can buy them, go to www.lsuagcenter.com/superplant.

Rick Bogren
Last Updated: 4/30/2013 10:19:08 AM

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