News Release Distributed 12/03/10

By LSU AgCenter Horticulturists Dan Gill, Kyle Huffstickler and Allen Owings

It’s time for cool-season bedding plants, and one of the flowers in this group gaining considerable popularity the past ten years has been dianthus. Pansies have long been the most popular cool-season bedding plant, but many new dianthus varieties are making this great, under-used cool-season flower better known to home gardeners.

The cool-season dianthus has long gone by the scientific name of Dianthus chinensis. Now, new hybrids and species are making dianthus an excellent choice for winter and spring landscape color. A new hybrid group is a cross between Dianthus chinensis and Dianthus barbatus. The Dianthus barbatus by itself is the source of some great-performing new varieties. These new species and hybrids are taller-growing and have potential as cut flowers.

The Telstar series of dianthus is a recommended group for Louisiana. Individual plants reach 12 inches tall and bear clove-scented flowers that are about 1 1/2 inches across. This series has good heat tolerance, so it will last until late spring. Numerous flower colors are available in the series, and you’re guaranteed success whether you choose to use them in a flowerbed or container.

The dianthus getting the most attention the last five years or so is Purple Bouquet. Flowers are not truly purple – they are more of a hot pinkish purple. Purple Bouquet is one of the Dianthus barbatus interspecific hybrids and is identified by the Mississippi Nursery and Landscape Association as a Mississippi Medallion plant that performs exceptionally well throughout Mississippi. It also has been outstanding in our LSU AgCenter landscape plant evaluations. Purple Bouquet dianthus reaches heights of about 24-30 inches, and blooms last longer into the warm season heat and humidity when compared with other varieties.

Melody Pink is similar to Purple Bouquet in growth habit. In addition, you may want to try Corona Cherry Magic, a recent All-America Selection. The Amazon series is another great group of dianthus. The Amazon group was named Louisiana Super Plants this fall and is available in Rose Magic, Cherry and Purple flower colors.

Dianthus performs best in full sunlight but also does well in some filtered afternoon shade. Flowerbed soils need to be loose, well-drained and fertile. Dianthus does well at a soil pH that’s slightly acid to slightly alkaline. Dianthus doesn’t tolerate wet soil conditions, so it is important to adequately prepare a landscape bed and irrigate properly.

You can plant dianthus from October through February on a 10- to 12-inch spacing to achieve a full landscape effect. At planting, or shortly thereafter, broadcast an application of a slow-release fertilizer over the entire bed. Depending on plant performance, a second light application may be beneficial in early spring.

Dianthus usually lasts well into mid- or late spring in Louisiana and can even grow and bloom through the summer with limited success. Although dianthus is a perennial plant, it likely will perform best when treated as an annual, cool-season plant from mid-fall through late spring.

Visit LaHouse in Baton Rouge to see sustainable landscape practices in action. The home and landscape resource center is near the intersection of Burbank Drive and Nicholson Drive (Louisiana Highway 30) in Baton Rouge, across the street from the LSU baseball stadium. For more information, go to www.lsuagcenter.com/lahouse and www.lsuagcenter.com/lyn.

Rick Bogren