If you want to get a head start on summertime color, you can gather your stored canna bulbs, or purchase new ones, and start them indoors several weeks before the weather is warm enough to plant outside. Cannas offer striped foliage and tropical color; starting them indoors is a simple process that will pay off quickly.
Wash and gently separate canna bulbs if they are clumped together so you can work with one bulb at a time.
Prepare your pots. If they do not already have holes for drainage, poke a few in the bottom. Place a layer of gravel in the bottom.
Combine the potting soil with your choice of fertilizer (bonemeal or superphosphate) according to the directions on the fertilizer package.
Fill the pots with the potting soil and fertilizer mix, leaving a few inches of space at the top of the pot.
Push one canna bulb down in each pot until it is completely covered. Don't worry about which end is right side up; if you see any growth, you can put it on the top. But whether or not canna rhizomes are planted right side up, they will grow and find the soil surface, according to BulbBlog.com.
Water every two days, keeping the soil moist but not soggy.
Set the small canna plants outside in the daytime to harden off before transplanting once the weather warms up in spring.
Transplant to your desired outdoor location before the canna plants are too large for the pot. Growth will slow down for several days to a week after planting; you can apply more fertilizer to help promote new root growth as the plants settle in.