By Norman Winter
MSU Horticulturist
Central Mississippi Research & Extension Center

If you had told garden center managers in the early 1990s that they would be selling hundreds of sweet potatoes for the landscape each year, they probably would have laughed hysterically. Now they are laughing all the way to the bank as the ornamental sweet potato has become a huge success story in just a few short years.

Sweet potato vines bring color and pizzazz to the landscape the entire growing season, and cover space almost as quickly as kudzu. Other than an insect or two, the ornamental sweet potato is foolproof.

If you still haven't tried ornamental sweet potatoes in the landscape, make 2003 the year you do. Select a site in full sun, although a little afternoon shade is quite acceptable. A farmer will tell you the sweet potato likes fertile, well-drained soil, and that's true in the landscape, too. This usually means amending with 3 to 4 inches of organic matter.

Incorporate two pounds of a slow-release, 12-6-6-fertilizer per 100 square feet of bed space while preparing the bed. Plant nursery-grown transplants at the same depth they are growing in the container, spacing 24 to 48 inches apart, depending on variety.

Give supplemental water during the long growing season. Flea beetles are known to occasionally make them unsightly, so treat with a recommended insecticide at the first sign of damage. Prune as needed to keep sweet potato vines contained in their allotted space.

Since winter has settled in, I want to get you stirred up a bit for the spring by telling you about some of the new ornamental sweet potatoes coming next season.

The hottest ornamental potatoes are known as the Sweet Caroline series. They are coming courtesy of the J.C. Raulston Arboretum in North Carolina, one of the most highly rated trial programs in the country. Though the potatoes are from the arboretum, they are being marketed through Paul Michells, a partner with Bodger Botancials.

There are four colors in the Sweet Caroline series: green, bright lime green, purple (actually a dark burgundy) and a bronze that has everyone talking. The bronze can best be described as rust. All of the series has deeply toothed leaves similar to the ever popular Blackie.

In addition to the Sweet Caroline series, look for Blackie, which is purple with deep lobes; Black Heart, which is also purple but with heart-shaped leaves; Margarita, with lime green and heart-shaped leaves; and Pink Frost, which is not as vigorous, but it is still outstanding with three-lobed leaves in variegated pink, green and white.

The ornamental sweet potato is the best annual groundcover today. The different colors intermingle for an effective display. They are unbeatable for cascading over walls and are easily capable of hanging down eight to 10 feet, if needed. Grow them in mixed containers and baskets, too. Combine them with coleus or cannas.

Try growing the bronze Sweet Caroline with blue verbenas, orange marigolds or white flowers. Grow the lime green Sweet Caroline in drifts with the burgundy Sweet Caroline.

It is fun to sit by the fire in the winter and contemplate new spring plants, and I promise you the Sweet Caroline series of ornamental sweet potatoes is not only worth dreaming about but buying in just a few short weeks.