Tradescantia "Sweet Kate" (Spiderwort)
I like this perennial for three reasons: its bright chartreuse foliage that brightens even the darkest of days; its vivid violet blooms that open in the morning and close at day's end; and for all of its various names - botanical, common, and, especially, "Sweet Kate." Tradescantia "Sweet Kate" grows to about 10 inches in sun or part shade in moist soils; it's a long bloomer, too. Zones 6-8. Quarts.