Warm-season landscape plant evaluations at the Hammond Research Station

Linda F. Benedict, Bracy, Regina P., Rosendale, Roger M., Owings, Allen D.

Blue Chip Buddleia

Redhead coleus

Sunny Side Up lantana

Supertunia Vista Silverberry petunia

PowWow Wild Berry Echinacea

Sky Rocket Pennisetum (Photos by Allen Owings)

Allen D. Owings, Regina P. Bracy and Roger Rosendale

Scientists at the Hammond Research Station evaluate ornamental plants for landscape performance under south Louisiana growing conditions. This information is then provided to nursery and landscape professionals as well as home gardeners for use in selecting plants that will help achieve desired results. Evaluations include annual flowers, herbaceous perennials, trees, shrubs, roses, crape myrtles and more. Much of the plant material studied is new to the horticulture industry while other plants may not be new but may never have been evaluated for their performance in south Louisiana. These tests are an attempt to make people aware of older plants that are worthy of being used once again.

New forms of purple fountain grass are now available. We know purple fountain grass, also called Pennisetum, from the 1980s, but new foliage types are now available. Fireworks was introduced two years ago and is being widely used and accepted in the industry. It is a red-foliage form. The new green-and-white variegated foliage form is Sky Rocket. The the new variety for 2012, Cherry Sparkler, has purple-and-white variegated foliage. These plants are best treated as annuals across much of the state. They prefer full sun and need minimum irrigation. Mature height by fall is 48-54 inches.

Many new butterfly bushes, also called Buddleia, have been available recently, including new dwarf forms that only get 2-3 feet tall, such as the Blue Chip variety from Proven Winners. Growers and landscapers also now have available the Buzz series dwarf varieties Ivory, Lavender, Magenta Improved, Sky Blue and Purple. The Flutterbys from Ball Horticulture with the petite types are very impressive and are better than many of the butterfly bushes previously available. They have good cold hardiness in the southern portion of the state and are considered low maintenance.

The new series of lantanas from Plant Introductions in Georgia are vigorous, mounding and good alternatives to the older, but still popular, New Gold and Silver Mound varieties. The first of the group were Chapel Hill Gold and Chapel Hill Yellow, which have been joined by Sunny Side Up, Miss Tara, Vanilla Ice, Apricot Sunrise and Sunset Orange. These lantanas have unique flower colors and add new interest to this older garden species.

Very late flower production on plants with spectacular foliage colors and shapes is characteristic of the newest varieties in sun-type coleus. Wasabi is the newest, most impressive coleus from Ball FloraPlant. It was developed at the University of Florida. These varieties join the list of other Ball FloraPlant releases – Trusty Rusty, Red Head, Indian Summer, Henna and Mint Mocha. Planted in late March through early May, their foliage color is enhanced in full sun.

Today’s purple coneflowers are not like your grandmother’s coneflowers. These are called Echinaceas. The PowWow series consists of PowWow Wild Berry and PowWow White. Other new purple coneflowers from Darwin Perennials are the Sombraro, Double Scoop and Mistical series. All are being evaluated at the Hammond Research Station for perennial potential, flowering and habit. Winter hardiness is needed in purple coneflowers, and these new varieties may be the answer.

Petunias can be warm-season or cool-season bedding plants in Louisiana. Professionals and home gardeners alike can easily be overwhelmed with so many varieties available.

The Vista Supertunias from Proven Winners continue to be great landscape performers. They finish in June landscapes about 10-14 days before Tidal Wave Silver petunias.

Varieties are Bubblegum, Silverberry and Fuchsia. More petunias performing well in 2011 were the new Suncatcher Pink Lemonade, the Whisper series (six colors) from Syngenta, Sun Spun Blue (new color in the series from Ball FloraPlant), Sangunas (10 colors) from Syngenta, and the Picnic series from Syngenta. Suncatcher Pink Lemonade has high consumer appeal but did not last nearly as long in the landscape. Although most petunias planted in Louisiana are the Wave and Easy Wave varieties, some of these warrant increased use. Plant petunias in fall (October) or early spring (February-March) for best results. They have reasonable cold hardiness and usually last until early June unless they are in shade for growing through summer.

Warm-season All-America Selection winners in the flower and bedding plant categories for 2011 are Arizona Apricot Gaillardia and Summer Red Jewel salvia. These have been nice landscape performers. Summer Red Jewel was best in trials at Hammond in 2011 and is a Salvia coccinea variety. It is smaller-growing, with less lodging and slightly darker flowers than long-time favorite Lady in Red.

A listing of the best Louisiana performers of the All-America Selection winners in the flower and bedding plant categories for 2010 includes Double Zahara Cherry zinnia, Zahara Starlite Rose zinnia, Double Zahara Fire zinnia, Moonsong Deep Orange marigold, PowWow Wild Berry Echinacea and Mesa Yellow Gaillardia.

This is just a small sampling of landscape plants that are being evaluated and studied at the LSU AgCenter Hammond Research Station. Plants are evaluated continually through the warm season of the year. The sun garden at the station, where much of this research is located, has 450 varieties planted at any one time. And more than 650 varieties are studied from March-November each year. Some plants evaluated have been named Louisiana Super Plants, and additional plant selections for this program are being named as a result of this research.

2011 People’s Choice Landscape Plant Award Winners from Open Houses and Field Days
Home Gardeners
Gold Winner – Guardian Blue delphinium
Silver Winner – PowWow Wild Berry Echinacea
Silver Winner – Guardian Lavender delphinium
Bronze Winner – Suncatcher Pink Lemonade petunia
 Bronze Winner – Tidal Wave Silver petunia
Bronze Winner – Peppermint Schnapps hardy hibiscus
Master Gardeners
Gold Winner – Guardian Blue delphinium
Silver Winner – Redbor ornamental kale
Bronze Winner – PowWow Wild Berry Echinacea  

Nursery and Landscape Professionals
Gold Winner – Carefree Celebration rose
Gold Winner – Purple muhly grass
Silver Winner – Sombraro Salsa Red Echinacea
Bronze Winner – Double Scoop Bubble Gum Echinacea
Bronze Winner – Mesa Bright Bicolor Gaillardia
Bronze Winner – Henry Duelberg salvia
Bronze Winner – Belinda’s Dream rose

Allen D. Owings, Professor, Regina P. Bracy, Professor and Resident Coordinator, and Roger Rosendale, Research Associate, Hammond Research Station, Hammond, La.

(This article was published in the winter 2012 issue of Louisiana Agriculture magazine.)

2/27/2012 11:08:44 PM
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