Canna lilies are large, colorful flowering plants that are not, in fact, true lilies. There are many varieties of cannas that can range from a few feet tall to as much as 10 feet tall, so make sure the place you select for your cannas is suitable for the height of the variety you will be planting. Cannas are tropical plants and are best planted long after the last frost and after the soil has warmed; the exact time will depend on your planting zone.
Select a location for your cannas that gets full sun. Cannas are tropical plants and thrive in warm, sunny locations.
Augment the soil with sand or organic material if it doesn't drain well. Soils that still have puddles of water 5 or 6 hours after a hard rain are not good for cannas. You will either need to augment these soils to improve drainage or look for a different location.
Dig holes for your canna rhizomes between 4 and 6 inches deep. The holes need to be 2 feet apart for full-sized cannas and about a foot apart for medium and dwarf cannas.
Put the rhizomes in the holes with the "eyes" facing up and cover them.
Once planted, thoroughly soak the soil. Cannas root very quickly. Maintain a moist soil until they have sprouted.