Anyone who's gardened in containers for long knows the magic formula -- for an effective container, you need a "thriller" (upright, showy plant), "fillers" (mounding plants on the sides), and "spillers" (trailing plants that cascade over the sides). And there can be no doubt that the most popular thrillers of all are the many selections of sweet potato vine.
Closely related to real sweet potato, sweet potato vines (Ipomoea batatas) don't form edible tubers. But who cares? Their eye-popping foliage creates a splash of bright color faster than just about any plant I know. The leaves can be yellow, chartreuse, burgundy, nearly black, red, light green, or variegated. They can be three-lobed, heart-shaped, or deeply cut like a Japanese maple leaf.
If memory serves, the first two selections offered were the bright chartreuse 'Margarita' ('Marguerite'), above, and the deep purple 'Blackie.' These extremely vigorous plants grow 8-10 feet or more in a single growing season, so you often see them planted as a seasonal ground cover. Next in line came 'Ace of Spades,' featuring heart-shaped, purple leaves.
It's a little less rampant than the first two, although 6 feet of growth in one season isn't out of the question. I like it a lot more than 'Blackie.'
These first three selections need pretty big containers, lest they conquer and kill pretty much all of their thriller and filler companions. Fortunately, there are options, like this one.
'Goldfinger"offers deeply cut, bright chartreuse leaves. It spreads only 24-36 inches. And thanks to the breeding work done at North Carolina State University, we now have the compact-growing Sweet Caroline Series and the Illusion Series as well.
How do you like Sweet Caroline 'Raven?' It's bushy and compact, growing only 2 to 4 feet. This is such an improvement over the older 'Blackie' that 'Blackie' should go into voluntary exile before it is sent by force to North Korea.
How about Illusion 'Garnet Lace?' Wow! I love the color. I love the finely cut leaves. But I do not love it more than my wife. That would be wrong of me. This one spreads 2 to 4 feet.
How To Grow Sweet potato vines like heat and sun. The more they get, the better they do. They'll grow in light shade, but their colors will be duller. Give them moist, fertile, well-drained soil. Plants in containers should be goosed with liquid fertilizer every two weeks. They're winter hardy as far north as USDA Zone 8. 'Margarita' and 'Blackie' form large tubers you can dig and save over winter in colder zones, but the others do not.
The most common problem people experience with sweet potato vines is discovering leaves riddled with holes. This is the handiwork of the sneaky golden tortoise beetle. 'Margarita' is its favorite. To control this pest, plant a different selection or spray your plants according to label directions with neem oil or spinosad.