An eye-catching addition to a decorative water garden, the Hardy Water Canna is an emergent aquatic plant that consists of approximately five bluish-green, tropical-looking, elongated basal leaves and a tall flowering stalk with a cluster of violet-blue flowers. Also known as Powdery Thalia or Powdery Alligator-Flag due to the powdery, water-repellant coating on the foliage. A regionally hardy plant native to the wetlands of the southern United States, it can endure mild winters, but roots must be submerged deep enough not to freeze. For use in your water garden, plant in a one-gallon container and submerge the pot 2" below the pond water surface, but no deeper than 6 in. during the growing season. Generally disease and pest-free.