In terms of fast-growing foliage plants it's hard to beat Sweet Potato Vine, or Ipomoea. This year we had a great new series in the K-State trials: SolarPower. These plants stayed compact (the plots looked like they had been edged with a string trimmer, but it wasn't necessary!) and were very well-branched. The deeply lobed leaves add a lot of texture to the landscape or container planting.
The Sweet Caroline series has been on the Prairie Star list for a long time, and the new color 'Sweetheart Lime' performs at an appropriately high level. The leaves are a bright green with a very subtle red around the margin that looks sort of like someone outlined it with a pen.
There are many great Sweet Potato colors to choose from on the Prairie Star list, with different growth habits ranging from sprawling to compact. The vining Sweet Caroline 'Sweetheart Red' has young leaves that are green and age to a dark red color. Very striking!
A neat development is the 'FloraMia Nero' cultivar of Sweet Potato that has flowers in addition to the attractive foliage. These plants aren't as vigorous and spreading as others, but they still have a nice presence and work well in combination plantings.
We run the annual and perennial flower trials for Kansas State University