Cannas are heat loving plants, and should not be planted out until all danger of frost has passed and the soil has warmed to at least 65 degrees F. Dig a hole in fertile soil with a good amount of organic matter and plant your rhizome with the pointy growing tips (eyes) facing upward; cover with 4" of soil. Water in well at planting, then wait for shoots to appear (which may take up to 2 weeks!) to resume watering consistently. If provided with consistent water, good fertility, and deadheaded regularly, Cannas will thrive, grow strong and tall without requiring staking, and bloom until frost.
To retain the rhizomes for future years in zones 7 and below, after frost, cut the stalks down at about 4" above the soil line and carfully dig and lift the root ball. Rinse well and allow the rizomes to dry and cure for a couple of days. Store them over winter in plastic with ventilation or lightly damp peat moss, coco coir, or burlap in a cool (45-50 F), dark place, checking periodically for overdrying, mold or rot. In the spring, large tuber clumps can be divided by gently teasing and breaking them apart, and then replanting.