Canna
Canna x generalis · Cannaceae Popular
Huge, paddle-shaped leaves, green, bronze or striped, topped with bright flowers in red, orange, yellow or pink from midsummer to frost. In cold climates the rhizomes are lifted for winter.
- Size
- 5 ft tall, 24 in wide
- Zones
- 8 to 11
- Light
- Full sun
- Flowers
- Early July to early October
- Pets
- No toxicity recorded
- Job in a bed
- Specimen
A bed built around canna
The planner designed this bed around canna when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 8, full sun. It chose the other plants from the 872 that suit those conditions, and says below why canna stands where it does.
The plants
- 1 Sea thrift × 8, pink
- 2 Leadwort × 20, blue
- 3 Foxglove beardtongue × 5, white
- 4 Tatarian aster 'Jindai' × 3, purple
- 5 Inkberry 'Gem Box' × 1, dark green leaves
- 6 Canna × 1, red
- 7 Pineapple lily × 1, white
Why this plant
- A classic partner for pineapple lily. Both are on this plan. A pairing gardeners have proved outranks a general rule.
- The only red. The one hot colour: every other flower here is cool or neutral.
Why here
- At the back. At 5 ft it is seen over pineapple lily (24 in) in front of it, and has nothing behind it to hide.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
- Beside pineapple lily. A recognised partner: the planner puts such plants together where it can.
Why now
- In flower for 14 weeks. From early July to early October.
- Fills a gap. For three of those weeks nothing else on the plan is in flower.
Planned as an English border: 6 of the 6 groups (100%) are drifts, longer along the bed than they are deep. Cool colours (pink, blue and purple) with red as the warm note, and white to calm things between them. The back corners are held by Tatarian aster 'Jindai' and foxglove beardtongue, the tallest plants on the plan.
The planner's own design check: 11 Excellent, 3 Good, 2 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where canna goes in a border
At 5 ft it belongs at the back of a bed. In the planner's ten height classes it is tall (4 to 5 ft).
Its job: specimen. A feature plant with a shape of its own. It stands alone with room around it, and repeats only at a distance.
The boldest leaf available for a sunny bed, and the plant that sets the tone of a tropical-style planting. One clump is a focal point. It needs heat, water and feeding to perform.
- A tropical effect
- Bold foliage for hot, moist beds
- Large containers and pond edges
What to plant with canna
Plants recorded as good partners for it, and what each pairing does:
- Hardy hibiscus: in flower together for nine weeks, from late July; grows up in time to hide its dying leaves; happy in the same moist soil.
- Anise sage 'Black and Blue': blue against orange, opposite each other on the colour wheel, if you choose those colours, in flower together for 14 weeks; grows up in time to hide its dying leaves; medium leaves against its bold ones.
- Daylily: in flower together for six weeks, from early July; grows up in time to hide its dying leaves; medium leaves against its bold ones.
Questions about canna
Does canna need sun or shade?
Canna grows in full sun (6 or more hours of direct sun a day).
It wants soil that stays evenly moist, rich in organic matter, and plenty of water.
What zones does canna grow in?
USDA zones 8 to 11. It is hardy to zone 8, which means it survives winter nights down to about 20 °F (−7 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does canna flower in my zone?
In zone 5 it flowers early July to early October. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 8 | Late June to early October |
|---|---|
| Zone 9 | Late June to early October |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should canna be planted?
20 in (50 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 cm), so a group knits into one patch.
It grows 5 ft (150 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many canna plants do I need?
At 20 in apart, set out in staggered rows:
- 4 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 14 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.
In the bed above, the planner used one in one group.
Is canna poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension and the ASPCA.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat canna?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
What can I plant to hide canna's leaves after it flowers?
A bulb's leaves have to be left to yellow for about six weeks after flowering, to feed next year's flowers. Plant it among perennials that come up late and spread wide, and they grow over the leaves as they fade:
- Blue false indigo: 4 ft tall and 4 ft wide, in flower late May to mid June.
- Itoh peony 'Bartzella': 3 ft tall and 3½ ft wide, in flower late May to mid June.
- Armenian cranesbill: 3½ ft tall and 3½ ft wide, in flower mid June to late July.
What does canna look like in winter?
Canna is underground: it dies back after flowering and waits as a bulb until spring. Mark where it is, so a fork does not find it first.
Is canna good for bees and butterflies?
Canna is visited by bees and hummingbirds.
It is a host plant: the caterpillars of brazilian skipper feed on its leaves. A butterfly can only lay its eggs on its host plants, so these do more for it than any nectar flower.
It is native to the United States.
In these guides
Every fact on record
- Type
- Bulb
- Size
- 5 ft (150 cm) tall, 24 in (60 cm) wide
- Plant
- 20 in (50 cm) apart
- Height class
- Tall (4 to 5 ft)
- Place in the bed
- Back
- Flowers
- Early July to early October; red, orange, yellow, pink
- Leaves
- Bold texture, herbaceous; green, bronze, variegated
- Shape
- Upright, clumping
- Hardy in
- USDA zones 8 to 11
- Light
- Full sun
- Soil
- Rich, evenly moist
- Water
- High
- Feeding
- Moderate, in spring
- Family
- Cannaceae
- Comes from
- Native to tropics and subtropics from FL, South America, & India
- Attracts
- Bees, hummingbirds
- Host plant for
- Brazilian skipper
- Stands up to
- Heat
Checked against NC State Extension and ASPCA poison lists. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.