I have grown “Margarita” (Ipomoea batatas), the chartreuse-leaved sweet potato vine, for several summers.

It makes a gorgeous contrast with purple plants like Persian Shield (Strobilanthus), and many other colorful annuals. In fact, the most spectacular spot in my garden is a stone wall above my driveway along which I plant a combination of Wave petunias, trailing verbena and sweet potato vine.

If I’m not vigilant, the sweet potato vine will rapidly swallow the other annuals in what seems like one gulp!

In the past few years, plant breeders have busily been introducing other shapes and colors of the ornamental sweet potato. A dark-purple version called “Blackie” came out very soon after “Margarita,” and now we have numerous others, heart-shaped, (both black and green), tri-color (green, white and pink) and bronze “Sweet Caroline” to name a few. I use these in many pots and hanging baskets.

The first time I planted them above the wall where they had regular garden soil to grow in, though, I made an astonishing discovery after the first frost. I had grown a fairly large crop of sweet potato tubers!

As gardeners, we have an innate horror of wasting anything so the question of what to do with this rather surprising bounty of nature is one that I have often been asked. The first question is usually, “Are they edible?” The answer is “yes.”

The leaves are also edible and can be used in Asian cooking. Once I found this out, I experimented with eating some. I found there is a reason some varieties are grown for their tasty tubers and some are grown for their beautiful leaves. I looked this issue up on the Internet and found it neatly put by the Iowa State University Extension Service bulletin: “Culinary properties may not measure up to varieties grown for their tasty roots instead of ornamental leaves.”

That said, the tubers taste sweeter after being cured for a week or so and are best in a stir fry or curry, where they are combined with other vegetables and interesting spices. I found that each variety I tried had a different tuber, different color flesh and different taste, so experimenting was fun.

You can always compost them, but if you want to try your hand at propagating, here’s how:

• Just after frost has blackened the foliage, you can dig up the tubers, being careful not to scratch or bruise them. Use a garden fork, just as you would for digging dahlias.

• Allow the sweet potatoes to dry for two to three hours and cure for a week to 10 days in warm temperatures and high humidity. A warm sunny window would be ideal. This will heal wounds and bruises and allow a corky layer to form.

• Once the tubers have cured, wrap them in newspaper to retard moisture loss, and store them in a cool location, preferably between 55 and 60 degrees F.

• In the spring, start new plants by placing one end of each tuber (or piece of tuber) in a jar of water. Fill the jar so that the top half of the tuber is above the waterline. Place it in a sunny window.

• In a few days roots will emerge from below the waterline. Two or three weeks later, leafy shoots will grow from the top. When the shoots have at least two nodes or three or four leaves, break the shoots off from their attachment to the tuber and insert them in potting mix, making sure that a node is below the surface of the medium.

• In two or three weeks, the cuttings will have rooted. These can be hardened off and used for plants once the soil temperature outdoors has reached 65 degrees.

• The small plants should be placed at least 2 feet apart when used in the garden. They are also very easily trimmed to keep in their space and not overrun their neighbors.

If you want to increase your plants in the spring and haven’t saved tubers, you can make stem cuttings from one you buy at the garden center. They will also root in water in four to five weeks.

This plant has much to recommend it in ornamental gardening. They have a vigorous growth habit, prefer full sun but will also grow well in partial shade and are drought-tolerant. In this case, that means they will wilt to show you they need more water but perk up rapidly once thoroughly watered.

If you’d like show-stopping summer color that you can eat in the fall, here’s your plant!

A WSU Master Gardeners of Chelan County column appears regularly in the Home, Garden section. Gloria Kupferman is one of several columnists featured.