Canna are summer blooming tropical perennial plants that grow up from underground rhizomes. They are moisture-loving plants, and some varietals in the genus can even grow with their feet in water. Canna rhizomes perform best when plump and well hydrated at planting time. This can easily be accomplished by a pre-planting soak in spring to recover from their dry winter hibernation. Rehydrate your canna rhizomes on the day or just the day before you plan to plant them.
Dust the canna rhizomes of any storage medium that has clung to them with a small, clean paint brush or soft, clean terry-cloth towel. Rub gently but do not disturb or abrade the skin.
Fill a clean bowl or bucket with tepid water to cover the rhizomes.
Soak the canna rhizomes for two to three hours in the tepid water. Set the bowl or bucket in a location with warm ambient temperatures around 70 degrees Fahrenheit.
Pull the rhizomes from the water and set on several layers of newsprint to drain. Plant the rhizomes in nutrient-rich soil garden or potting soil with the eyes facing up toward the sun; water well.