Ornamental Dinner

     I was changing out the flower boxes today at work, trying to make them look a little more Fall-ish.
The plants that were in there were looking a little tired anyway, so I yanked them out. There was some Salvia spp. and Penta spp. and some Potato Vine (Ipomoea batatas).
Well, when I pulled the potato vine out, look what came out with it.

     Yup, those are really sweet potatoes!
     Southerners know these tasty tubers because when they come into season, you see people selling on just about every other street corner. The garden varieties of the edible sweet potato have been selected due to their flavor while the ornamental varieties were selected for their colorful foliage and trailing nature. The most common of the decorative cultivars include ‘Blackie,’ and ‘Marguerite’. While the first has very dark purple foliage, the second is a bright chartreuse most commonly seen spilling over the sides of spring planters. These came from 'Marguerite'.

     These plants can grow quickly and will take over. Even when planted small, they can grow easily 5 to 10 feet in a single season, so give them plenty of room or prune them to stop them from eating your small children and Chihuahuas. Their trailing vines are much better at hanging down over the sides of containers, hanging baskets, or creeping along the ground than they are at climbing up a pole or trellis.
      Sweet potatoes, both the one grown for food and the ornamental one, prefer moist, well-drained soil in full sun with a moderate amount of water. They can tolerate light shade if necessary, but the ornamental one will be less dramatic. They are cold hardy in U.S. Department of Agriculture plant zones 9 through 11, but you can also dig them up in fall and store them over winter for spring planting. Here in my zone 8, I have seen them overwinter in the ground and come back with a vengeance the following Spring.
     Propagation is very easy. If you overwinter the tubers, treat them just like a potato. In the spring cut them up into chunks with each section containing one “eye” (the little nub) and plant separately. Before they get hit by the first frost, you can start new plants from 4 to 6-inch cuttings. Remove the lowest leaf and stick the cut end in a container filled with vermiculite or your favorite potting mix that is moist and well-draining. A little root hormone will definitely not hurt. Keep the rooting medium moist, but not wet. You may also find that the plant has rooted itself along the trailing vines. If it has, carefully dig it up at the point it has rooted, cut it free from the mother plant and place it in a pot with some fresh soil.  You can grow them as houseplants through the winter in a sunny window.
     Although relatively carefree, there are a few problems to watch out for. Pests include the golden tortoise beetle, potato flea beetle and the sweet potato looper which is a caterpillar. Mainly these pests chew holes in the leaves, such as seen above. Natural enemies of these pests will help control them as long as pesticides specific for the pest are used and avoiding the use of broad-spectrum insecticides, if at all possible.

Golden Tortoise Beetle- Photograph by Lynette Schimming, bugguide.net.

     Verticillium and Fusarium wilts are two of the most common fungal diseases of sweet potato plants. If either one of these fungal diseases crops up you will know it is present by the yellowing of the leaves that begin at the bottom of the plant and work its way up. If you discover a fungal infection, apply a quality fungicide that is designed for use on vegetable crops, such as Daconil Fungicide Ready-to-Use.

The question has been raised, are the tubers from the ornamental sweet potato vine edible?
Absolutely!
     They are safe to eat, but reportedly not really tasty. Personally, I haven't tried them, nor have I tried the leafy green tops which are edible too. From what I have heard, if you’ve never tried eating potato vine leaves, you’re missing out on a tasty, highly nutritious veggie.

     It's not a great picture, but this is 'Bright Ideas Black' sweet potato. Everything you read above goes for it too.
     There has been a push for incorporating edibles into the landscape, so if you are growing the ornamental sweet potato, you are already killing two birds with one stone! It may not be super tasty, but in a pinch, it is a very healthy food.
So, Bon Apetite!
If you have any questions concerning this article or any of my others, please feel free to comment, or send me an e-mail to TheCitrusGuy@netzero.com
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Happy Growing!
Darren