Canna Lily Planting Guide

Seeking a bit of visual quiet in your garden this season? Don’t plant cannas. Canna lilies are big and boisterous, never timid or tame. Gotta love this about them.

These bold plants deliver a punch, with tropical foliage that’s ribbed and often purple, bronze or striped. And the flowers; upright clusters of four to more than a dozen in electric shades of red, orange, yellow, gold and more. Add a hefty helping of speckles, splashes and stripes for even more excitement. Dazzling!

Choosing a Planting Site

Canna lilies originate from tropical areas in Central and South America. They love the sun; the more you give them, the happier they are. Cannas require a minimum or four hours of sunlight. With giant leaves that catch the wind like sails, it’s usually best to select a site that’s not too breezy.

Soil Prep

Cannas prefer moist but not soggy soil. Average garden soil or a commercial potting mix will work well. Adding a slow release fertilizer when you plant and/or a rose or tomato fertilizer midseason provides nutrients to support the substantial growth cannas produce each season. For beds, mulching after the rhizomes have sprouted helps keep the soil cooler and reduces watering needs.

When to Plant Cannas

Plant outdoors when frost danger has past and your soil is about 60 degrees, which occurs when days and nights are warm. Canna lilies are tropical plants and really don’t appreciate cold soil or cold nighttime temperatures. A good rule of thumb is to plant your cannas outdoors when temperatures are suitable for tomatoes.

How to Plant Canna Rhizomes

Canna lily rhizomes typically have several eyes or growing points, similar to those on a potato. Place your rhizomes horizontally in the soil with the eyes facing upwards. If you can’t find the eyes or they are opposite sides of the rhizome, not to worry. The eyes will sprout even from a downwards facing position and will find the soil surface. Cover with 2” of soil. Water well to settle the soil around the bulbs. Keep soil very lightly moist until sprouts develop and then gradually give the plant more water as it grows larger. Cannas typically take 2-4 weeks to sprout in soil that is 60 degrees or warmer.

Canna Spacing

Plant cannas 12 – 18” apart in beds and borders. In containers, you can plant more closely with partners. Keep in mind that a small amount of soil supporting a number of plants in a mixed container will require supplemental nutrients.

During the Growing Season

Cannas require little care during the growing season. Trim off spent flowers to keep the plants looking their best. Snip the occasional leaf, wash and use as an exotic serving platter liner for crudités or cheese and crackers

Saving Rhizomes at Season’s End

Gardeners living in zones 7-10 can leave their cannas in the ground for next year. As temperatures cool and the season winds down, your cannas will prepare for dormancy. Their leaves will yellow. This usually occurs between September and December depending on your climate. When you see this, stop watering.

In colder climates you can choose to treat cannas like annuals, ignore them when the cold arrives and start over in the spring. Or you can lift the rhizomes and overwinter indoors. To lift, wait until the leaves have yellowed, dig the rhizomes, brush off the soil and let them dry on newspaper for several days. Store the rhizomes in peat moss in a cool (45-50+ degrees), well ventilated area. Note the variety; we always think we’ll remember . . . and don’t. Replant come spring and enjoy for another season.

Insider Tips

  1. For early garden pizzazz, start your cannas indoors about six to eight weeks before the ideal outdoor planting time. Follow planting instructions above, using pots or trays to get your rhizomes sprouting.
  2. Individual growing conditions may influence height, leaf size and color. Less than full sun sites typically produce taller plants with larger leaves.
  3. New leaves sprout from the main stem curled into a tight roll. Look for the long tubes of foliage and watch as they unfurl to show off their colors and veining patterns.
  4. After flower panicles have finished blooming, most cultivars develop large, round, prickly seed pods. Unless you plan to use the pods in flower arrangements, it’s a good idea to trim off spent flowers. This directs the plants’ energies into producing more flowers rather than developing seeds.
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Success Snapshot

Light: Full to 3/4 day sun

Soil: Average soil

Depth: Cover with 2” of soil

Water: Average moisture

Uses: Large containers, beds and borders

Tip: Dead head to encourage rebloom

GUIDE: Canna Lily Planting Guide

They Start Out Looking Like This: