Turn-of-the-century gardeners so loved cannas that they grew them from seed, but this isn’t easy; better to leave propagation to experts and plant canna rhizomes instead.
Cannas are commonly referred to as a “bulb” although they are not a true bulb; cannas multiply beneath the soil from a fattened extension of the stalk called a “rhizome.”
If you grow from seed, be aware that the germination rate is low and the seeds need to be filed or given an acid bath to break down their hard coat.
Dig a hole 2 to 3 inches deep and set the rhizome in the hole, eyes up. (And if you happen to plant with the eyes facing to the side or down, no worries! The new growth will easily find its way toward the sun.) Cover the rhizome with one to two inches of soil. Tamp firmly. Water thoroughly.
Space rhizomes 1 to 4 feet apart.
Cannas are slow to sprout and do not require much water until you begin seeing signs of growth. Sometimes is takes as many as three weeks for cannas to sprout. Once sprouted, water cannas at least once a week by slowly soaking the area around the roots.
During the hottest weeks of the summer, give the plants a good soaking drink of water every other day.