Carlos Smith old fashioned verbena. (Photo by Allen Owings. Click on photo for downloadable image.)

Princess Dark Lavender verbena. (Photo by Allen Owings. click on photo for downloadable image.)

News Release Distributed 01/20/12

One of the great flowers that continues to be popular in our Louisiana landscapes is perennial verbena.

We have native verbena growing along roadsides in Louisiana, and many species of verbena are familiar to gardeners. But the species Verbena canadensis and its hybrids are probably our best performing. This herbaceous perennial is a reliable performer for 2-3 years after its original planting.

Late winter and early spring is the best time to plant perennial verbenas. Place plants about 2 feet apart. This may sound like a considerable distance, but once growth begins, this will be an ideal spacing.

These plants need a well-drained site, and full sun is preferred over partial sun, partial shade or shade. Soil pH is not critical – plants will do fine in slightly acid, neutral and even alkaline soil conditions.

Irrigate only to aid the plants in establishment and to assist them during excessively dry periods. Perennials verbenas are very drought tolerant. But they have powdery mildew and root/stem rot problems when overwatered or during periods of high rainfall. Mulch them with pine straw after planting, and fertilize with a slow-release fertilizer for best results.

We have many varieties of perennial verbena available. Homestead Purple is the most popular and most readily available in Louisiana. This was an old Louisiana Select-promoted plant in the 1990s and is still popular today. Home gardeners don’t buy Homestead Purple as much these days because many other varieties now available have expanded the flower color range for these great plants.

The Aztec series is popular, as are the Wildfire, Magalena, Lanai and others. Verbenas are available in a wonderful range of flower colors from light blushes and pinks to dark reds, blues and purples. Some people continue to prefer the older varieties, but they are harder to locate. These include include Texas Appleblossom (which is sold in Mississippi as Port Gibson Pink), Snowflurry (a nice white-flowering variety), Fiesta (magenta flowers), Summer Blaze (red), and Taylortown Red (red). These are still around in the nursery trade and can be found in Louisiana, but it may take a little searching.

The Biloxi Blue variety is also called Princess Blue or Princess Dark Lavender and is part of the Southern Living Plant Collection, which also includes Princess Blush. A new variety that we hope will be made available by the LSU AgCenter in the next couple years is a “found” bicolor verbena discovered by retired AgCenter horticulture agent Carlos Smith in central Louisiana.

Perennial verbenas flower best from late winter through spring and then in late summer through fall. Some flowers also are present in summer, but the hottest part of the year is not the prime time for this plant.

Pruning back plants after each flowering cycle is completed encourages new growth that will produce flowers when the next ideal time comes. Stem cuttings from the pruning process will root easily.

Butterflies love perennial verbenas.

LSU AgCenter research has found that most perennial verbenas come back the next year but may need replacing once every 3-4 years or so. They are not “long-term perennial” but are definitely worth planting and then enjoying several times during our gardening seasons.

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 or www.lsuagcenter.com/lyn.