Cannas are tropical and subtropical flowering plants with large, banana like leaves. They can be grown as annuals in cooler regions, where they add an instant touch of the tropics to gardens. A surge in interest and hybridizing has resulted in a dazzling array of cannas to choose from. Cannas are often grown from their foliage alone. The large, paddle-like leaves resemble banana leaves and come in greens, blue-greens, variegations and stripes. Canna flowers come in shades and combinations of yellow, orange, red and pink and are borne on tall stalks coming out of the foliage.