Black Knight Cannas, with their lush tropical, almost black, foliage and showy, vibrant red flowers, sometimes with darker edges, make borders and beds come alive with bright color all summer. Long valued by park and municipal gardeners, home gardeners now realize the value of these new hybrids as each year their popularity grows. Hummingbirds especially like these! In most areas you'll need to dig up the tubers in fall and store them indoors. After frost kills back the foliage, dig the tubers and store them in a cool, dark, frost-free place.