The canna is a rhizome growing tropical perennial native to Central and South America and areas in the southeastern United States. Cannas are hardy to plant outdoors in USDA growing zones 8 and higher, but will also grow in lower zones as long as you remove the rhizomes from the ground and winter over indoors. Plant cannas in a sunny location in the spring once there is no longer a danger of frost and the soil begins to warm.
Prepare the planting area for cannas by working the soil to a depth of 12 inches with a tiller. Work 2 inches of organic compost into the loosened soil.
Dig a planting hole that is 4 to 6 inches deep and wide enough to hold the rhizome. Set the cannas rhizome horizontally into the hole with the eyes facing up and cover the rhizome with soil. Plant the cannas rhizomes 12 inches apart.
Water the cannas well after planting to moisten the soil to a depth of 6 to 8 inches. Provide supplemental water two to three times a week to keep the soil evenly moist during the growing season. Monitor the soil moisture level during dry periods as the plants may require additional water applications.
Fertilize cannas in early spring by applying 2 pounds of a 5 percent nitrogen fertilizer for each 100 square feet of garden space. Repeat the fertilizer application each month during the summer to stimulate plant blooms.