Cannas are easy to grow and can lend a tropical accent to the Ohio garden. Although they thrive in full sun, they are generally low-maintenance plants. Cannas are started with rhizomes and, in Ohio, starting them indoors in mid-March, is recommended by agriculturists with Ohio State University. By late May, or the last frost date for your area of Ohio, the Canna will be ready to be transplanted into the garden and put on a colorful show all summer.
Fill planting pots to within 1/2 inch of the rim with potting soil.
Bury the Canna rhizome 2 inches deep and cover with soil. There is no upside-down for a Canna rhizome, so just place it in the planting hole and cover it with soil.
Water the planted rhizome until water runs out of the pot. Place the pot in a shady area and keep the soil moist, not soggy until the Canna is ready to be transplanted.
Choose an area of the garden in which to plant the Canna. It requires all-day sun and well-drained soil.
Amend the planting area by mixing 3 to 4 inches of compost into the top 8 inches of soil. A gardening fork works well for this task.
Transplant the Canna into the garden after all danger of frost has passed. In Ohio, this generally occurs in mid-May. Dig a hole the same depth as the pot in which the Canna is growing and twice the diameter. Carefully remove the Canna from the pot, place the roots into the hole and fill the hole with soil. If you are planting more than one Canna, space them 12 to 18 inches apart.
Water the Canna until the soil is very wet and begins to puddle. Cannas in Ohio don’t require a lot of water, but don’t let the soil dry out completely.
Fertilize the Canna three weeks after planting. Experts at Ohio State University suggest that the best formula for Ohio-grown Canna is 5-10-5 at a rate of 3 pounds per 100 square feet. Canna should then be fertilized once a month. Always water prior to fertilizing.