Bulb · Cannaceae
Canna Lily
Canna × generalis
Hand it full sun, rich moist soil, and summer heat, and the canna fires up bold leaves and flame-bright flowers straight through to frost.
Full sun
Every 2–5 days
50–95°F · 10–35°C
70–120 days
Overview
Canna lily drops a tropical look into a temperate garden, swinging out broad paddle-shaped leaves and tall spikes of bold flowers. The name misleads, since it is not a true lily at all but a rhizome-rooted perennial in the family Cannaceae, far closer kin to gingers and bananas. It grows fast and grows big, running from a knee-high bedding type up to a giant pushing near 8 feet (240 cm) tall.
Heat and water are what fuel it. Drop it into full sun and rich, moist soil, keep the water coming through the hot months, and it pays you back with bloom from midsummer right up to the first frost. It powers through conditions that flatten fussier plants, which is exactly why gardeners grab it to anchor a bed or load up a big pot.
Hardiness draws the one firm line. In zones 7 to 10 the rhizomes coast through winter in the ground, but anywhere colder you lift and store them once frost knocks the plant down. Dividing those rhizomes every couple of years keeps the clump charging along and hands you free new plants.
Care
The short version: full sun, rich soil kept evenly moist, and plenty of warmth. Feed monthly through the growing season, split the clump every few years, and lift the rhizomes for winter anywhere the ground freezes.
Light
Canna craves full sun, six hours a day at the very least, to flower at full tilt. It will take partial shade or partial sun, but the bloom thins out and the stems stretch and lean toward the brightest spot.
Water
Keep the soil evenly moist, above all through active growth and hot spells. Canna ranks among the rare garden plants that put up with some standing water, yet an established clump can ride out a short dry stretch. Water every 2 to 5 days in the heat of summer.
Soil
Set it into rich, moist, well-drained ground worked through with plenty of organic matter. It shrugs at pH, taking anything from 6.0 to 8.0, but drainage is the part that truly counts, since soggy soil rots the rhizomes.
Temperature
Canna runs on heat, growing happily from 50°F to 95°F (10°C to 35°C). It carries zero cold tolerance, so the first frost cuts it down and the rhizomes call for lifting anywhere winters freeze.
Humidity
Average outdoor humidity suits it just fine, with no number to track. Its tropical roots mean it never balks at muggy summer air.
Feeding
Feed monthly with a balanced all-purpose fertilizer through spring and summer while the plant powers along. For an in-ground clump, a soil test points you straight to how much it actually needs.
Pruning
Snip off the spent flower stalks to keep fresh blooms rolling in and the plant looking sharp. After the first fall frost in cold zones, cut the foliage back to 2 to 3 inches (5 to 8 cm) before you dig the rhizomes for storage.
Repotting
Canna skips routine repotting, but a crowded clump asks for dividing every 2 to 3 years. Watch for dense growth, fewer flowers, or rhizomes shoving up through the soil, all signs the plant has outgrown its room.
Size & spacing
Plants run from 18 inches to 1.5 to 8 feet (46 to 239 cm) tall depending on the type, so check the variety before you set it. Space the rhizomes 1.5 to 3 feet (45 to 90 cm) apart to hand the big leaves room to spread.
When to plant
Canna runs on warmth and won't take frost. In cold zones, get the rhizomes going indoors a month or so ahead of the last frost, push them outside once the soil warms up, and the flowers roll in from midsummer through the first fall frost.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Start rhizomes indoors in pots 3-4 inches deep about 4-6 weeks before the last frost in cold zones.
- Plant: After the last frost when soil has warmed, planting rhizomes 3-4 inches deep and 18-36 inches apart.
- Harvest: Blooms mid-summer through the first fall frost (about July to September).
Hardiness
USDA hardiness zones: 7–10
Temperature: down to -18°C
Troubleshooting
Almost every canna problem traces back to wet soil or a few familiar pests, and it surfaces on the leaves or the rhizomes. Spot it early and you can usually rescue the plant or the rest of the clump. Match what you see below, then move before it spreads.
Mushy rhizomes and growth that stalls out or keels over
You're dealing with rhizome rot, and wet soil that never drains is nearly always the trigger. Dig up a rhizome and you'll meet brown, soft, foul-smelling tissue, sometimes with bud rot or bacterial blight riding along. Toss every rotted piece, replant only the firm sections into ground that drains, and pull back hard on the watering.
Fix:
- Lift and discard rotted rhizomes
- Replant healthy firm sections in well-drained, organically rich soil
- Reduce watering and improve drainage
New leaves emerging streaked, mottled, or twisted
Yellow streaking and warping that shrug off every drink and feeding usually flag canna mosaic virus or aster yellows. Once a plant catches it, no cure brings it back. Pull it, destroy it, keep sap-feeding insects under control, and never propagate from rhizomes you think carry the virus.
Fix:
- Remove and destroy infected plants to limit spread
- Control insect vectors
- Do not propagate from infected rhizomes
Foliage chewed, punched with holes, or rolled tight
Rolled or webbed leaf edges give away the canna leaf roller, far and away the usual offender. Japanese beetles, slugs, and snails handle the bigger, blunter chewing and trail slime as they go. Pluck the pests off by hand, peel away the wrecked leaves, and rake up plant debris so fewer survive into next season.
Fix:
- Hand-pick caterpillars, beetles, slugs, and snails
- Remove and destroy rolled or damaged leaves
- Apply an appropriate labeled control if infestation is heavy
Toxicity
Great news for pet owners and parents: the canna lily is safe. The name throws people off, but it is not a true lily and packs none of the poison those plants carry. The ASPCA lists it as non-toxic to cats, dogs, and horses, and the starchy rhizome even lands on the plate as food in some countries.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Plant it freely around cats. The ASPCA rates canna as non-toxic, so a curious nibble brings no poisoning.
Dogs None
Dogs face no toxicity here. One that chews a leaf or digs out a rhizome risks nothing worse than a touch of stomach upset from the roughage.
Horses None
Horses can graze right next to canna unharmed, because the ASPCA clears it as non-toxic to them.
Rabbits Safe
The foliage carries no known toxin, so rabbits roaming the garden are perfectly fine.
Livestock Safe
Cattle, goats, and sheep take no harm from canna; the plant holds nothing that troubles grazing animals.
Birds Safe
Birds stay safe around canna, and the hard seeds pass straight through without harm.
People Safe
No risk to kids or adults. Some parts of the world even cook the rhizome as a starchy food.
No special handling required for toxicity; wear gloves if sensitive when dividing rhizomes.
Varieties
Cannas span squat bedding plants to towering giants, in colors from soft cream to fiery red. A handful of names keep coming up, and these are the ones to know.
Tropical Series
A compact, seed-grown line bred to stay small enough to thrive in containers and bedding.
South Pacific Scarlet
An award-winning cultivar raised from seed that pushes out bright scarlet flowers.
Canna indica (Indian Shot)
The wild canna, flashing flame-red flowers and hard round seeds that earned it the name Indian Shot.
How to propagate
Canna multiplies most reliably from division, which keeps a variety true, while patient growers can also raise it from its hard, shot-like seeds.
DivisionEasy
Spring at planting time, or in fall when lifting rhizomes for storage; divide crowded clumps every 2-3 years. · 2 to 6 weeks
Division is the quick, dependable way to multiply canna and to keep a variety running true. Cut the rhizomes apart in spring or while you lift them in fall, leaving each piece with at least one eye, then dry the cut surfaces for a few days before they head back into the ground. Split a crowded clump every 2 to 3 years and the fresh pieces root in roughly 2 to 6 weeks.
SeedModerate
Spring, started indoors. · Several weeks to germinate
Raising canna from seed runs slower and less sure. The hard-coated seeds, the very ones that earn the name Indian Shot, want nicking and a soak before they break dormancy, and germination still drags on for several weeks. Sow them indoors in spring, but count on seed-grown plants may not come true to type.
Myths
The canna lily is a true lily and is just as toxic to pets as other lilies.
Canna isn't a lily in the slightest. It sits in the family Cannaceae, not Liliaceae, and the ASPCA lists it as non-toxic to cats, dogs, and horses. That shared name is the only link it has to the lilies that actually harm pets.