How to Plant Canna Lilies in Ohio
Canna lilies (Canna spp.) are perennial summer-flowering plants grown for their striking lily-like flowers. Canna lilies are hardy in U.S. Department of Agriculture hardiness zones 7 to 10.
While in warm climates they can be left in the ground, in Ohio they are grown as annuals and the rhizomes are overwintered indoors.
Canna Lily Identification
While they are often referred to as flowering bulbs, cannas are not true bulbs. Instead, they grow from a fleshy underground stem known as a rhizome. They are also not true lilies.
Canna lilies typically have heights between 4 and 6 feet, though there are smaller dwarf cannas as well as even taller cultivars that can be up to 8 feet tall. They have oversized leaves that resemble paddles.
Canna flowers come in a variety of warm-toned colors. There are cultivars with yellow flowers, red flowers, orange flowers and pink flowers.
When to Plant Canna Lilies
Canna lilies do not tolerate cold soils. Therefore, it is imperative to wait until soil temperatures have warmed enough and frost is no longer a threat in order to plant rhizomes.
In Ohio, this may mean waiting until after late spring, even after Memorial Day, to move canna lilies outside into the garden.
In Ohio and elsewhere, canna lilies should be planted only after the last frost of the spring.
How to Plant Canna Lily Bulbs
Plant canna rhizomes at a depth of 4 to 6 inches. Allow 2 to 3 feet of space between each plant. These plants grow best when they receive full sun, so consider light when selecting a location for planting cannas.
Organically rich soil is a must for canna lilies. Therefore, you may need to amend the soil accordingly with compost to make sure it has enough organic matter to support these plants.
Canna lilies grow best in moist soil and benefit from a layer of mulch. Make sure to plant canna rhizomes in well-draining soil, however, as overly wet soil can cause the rhizomes to rot.
Winter Care of Canna Lilies
Because they are not winter hardy in Ohio, which falls in USDA zones 5 and 6, if you grow canna lilies in this state, you need to dig up the rhizomes and overwinter them indoors to be replanted again the following spring.
Dig the rhizomes in autumn when the leaves have yellowed or died after the first frost, but before the ground has frozen. It is important not to remove the rhizomes too soon in order to allow them to develop enough food to sustain the plants.
In Ohio, where they are not winter hardy, dig up canna lily rhizomes in the fall and store them in a cool, dry place until spring.
Storing Canna Lily Rhizomes
After digging up the rhizomes, rinse them with water to remove excess soil, then allow them to dry for a week before storing them in a dry medium like peat moss or vermiculite. The rhizomes should be kept in a cool location where temperatures do not get any colder than 40°F.
Rhizomes that have grown large can be divided and grown as individual plants in the spring.
Since beginning her career as a professional journalist in 2007, Nathalie Alonso has covered a myriad of topics, including arts, culture and travel, for newspapers and magazines in New York City. She holds a B.A. in American Studies from Columbia University and lives in Queens with her two cats.