Canna lilies are beautiful flowers that can thrive inside or out with the right soil and enough light.
Cannas should be planted in organic soil rich with compost, coffee grinds, manure and egg shells. Cannas like plenty of full sun, so plant your canna where it will receive at least 6 hours of direct sunlight every day.
Plant the rhizomes in the ground after the last frost, in early spring. Plant the rhizome horizontally, with the growing points facing upwards if they are visible. Plant them 2 to 3 inches deep and at least 18 inches apart so they have room to grow. Keep the new rhizomes moist but never wet, to avoid rot. A thick layer of mulch around the cannas is beneficial for healthy growth.
Surviving Cold Weather
Potted cannas may be brought into your home where they can grow all winter in a sunny spot. Water them lightly and supplement their soil with additional fertilizer, such as fish emulsion (de-scented) or a cup of composted material.
Zones 7 and below are too cold for cannas to survive outdoors; let the first hard frost kill the foliage before digging the cannas up and bringing indoors to a temperature of 50 degrees, where your canna will remain dormant until spring. During this time, water very lightly to avoid rot and ensure beautiful cannas in the spring.