canna

( KAN - nuh )

At-A-Glance Information

These flowering perennials are commonly called Canna Lily. These plants grow from rhizomes and can take full sun and regular to ample water during growth and bloom periods. They have showy leaves and flowers, and are great low-maintenance additions to any garden, adding a tropical look to containers and planting beds. Leaves and flowers vary in color, and blooms appear in summer and fall. Cannas are native to American tropics, though they have naturalized in many places around the globe. Use Canna in mixed beds and borders, in tropical or pollinator gardens, or around pools or other water features.

Canna Species and Varietals

The genus Canna is a member of the plant family Cannaceae and includes 10 species. Canna Lilies do best when grown in USDA hardiness zones 7-10 or Sunset growing zones 6-9, 12-24, H1 and H2. To find your zone, click here: Zone Map.

Canna bangii (Canna musafolia) (Bang's Canna, Bang's Indian Shot)
This species is native to Peru and Bolivia and plants reach up to 13 feet tall at maturity. They produce green foliage that is downy and soft. Flowers are orange to red in color, and bloom from August through October in the plant's native range.

Canna coccinea (Canna indica) (Indian Shoot)
This northern Argentinian native plant reaches about 6 feet tall when in bloom, and produces heads of raspberry-red flowers above green foliage. Blooms are most profuse from August through October, but can bloom year-round in warm climates. It is considered an invasive species in New Caledonia.

Canna compacta (Canna indica)
This species, native to southern Brazil and Argentina, is a perennial that reaches about 6 feet tall at maturity and produces orange and red flowers that bloom from August through October. Varieties include 'Robert Kemp', 'Tiki Torch', and 'Tiki Tourche'. 

Canna discolor (Achira, Water Canna, Louisiana Canna)
The native range of these plants is from southern Mexico through Colombia. Achira flowers from August through October and produces bright red flowers atop tall stems. This species is considered invasive in many parts of the world, including Australia, New Zealand, South Africa, Europe and the southeastern United States.

Canna flaccida (Bandana-of-the-Everglades, Golden Canna, Southern Marsh Canna, Yellow Canna)
Reaching up to 5 feet tall, these plants are native to central, south, and east United States, and have naturalized elsewhere. This species is a parent to many of the early hybrid Canna cultivars, and produces yellow flowers. Blooms emerge from August through October in the plant's native range. These plants like to be grown in wetland environments, and are considered invasive in India, the Philippines, and Australia.

Canna glauca (Canna jacobiniflora) (Water Canna, Louisiana Canna)
These plants are native to wetlands in the tropical Americas, and have naturalized elsewhere. They can reach 3-6 feet tall and have blue-green foliage. Flowers are pale yellow and bloom August through October in the plants native range. Varietal 'Erebus' has salmon-pink flowers and blue green leaves, and reaches 4-6 feet tall. 

Canna indica (Canna amabilis) (Indian Shot, African Arrowroot, Edible Canna, Purple Arrowroot, Sierra Leone Arrowroot, Achira, Cana-da-India)
Native to much of South America, these plants have naturalized in many areas of the globe, and grow to reach between 1.5 and 8 feet tall when in bloom. There are many subspecies and cultivars in this species, with varying heights, flower colors, and foliage. This species is considered invasive in many parts of the world, including Hawai'i, Fiji, Australia, and South Africa.

Canna iridiflora (Peruvian Canna, Iris Canna Lily)
Distinguished by its dangling flowers, this species of Canna reaches up to 16 feet tall and has green foliage edged with darker hues. Flowers are pendant-shaped and pink in the true species, blooming in late summer and fall. The species is native to Peru, Columbia, and Costa Rica, where it grows in cloud forests.

Canna paniculata
These flowers are native to South America, Mexico, and Costa Rica. They reach 16 feet tall and produce green leaves and orange to reddish flowers with thinner petals than most species in the genus. Leaves are green. Blooms pop from August through October.
Canna Varietals and Cultivars
Canna cultivars are generally divided into three distinct groups: Foliage (or Année), Crozy and Italian. The foliage group is grown for their notable leaves, and the Crozy group (sometimes called the Gladiolus flowering group) has varieties bred for their packed flower spikes. Finally, the Italian group has blooms that are more spaced apart, and have wider petals than the plants in the Crozy group. The following list of cultivars represents some of the more commonly found and sought-after varieties of Canna.
'Bengal Tiger' ('Striata')
4-6 feet tall, with yellow-striped green leaves and orange blooms.
'Tropicanna' ('Phasion')
4-6 feet tall, with bright orange blooms and purple foliage with green, yellow, pink and red stripes.
'Tropicanna Gold'
Gets 4-6 feet tall and has striped green and gold foliage. Flowers are yellow-orange flowers with flecks of darker orange.
'Tropicanna Black'
Gets to 4-6 feet tall and has deep bronze to brown foliage. Flowers are red when new, and fade to orange.
'Black Knight'
Black-bronze foliage and deep red, velvety flowers. Gets 4-6 feet tall.
'Ermine' ('Ermine White')
Gets 3-4 feet tall and has white flowers.
'President'
​Scarlet flowers.
'Intrigue'
Orange flowers bloom on a 6-8 foot tall plant.
'Yellow Futurity'
Smaller species, getting to just 24-30 inches tall. Has yellow flowers and green leaves.
'Red Futurity'
Smaller species, grows to 24-30 inches tall. Flowers are red and leaves are striped green.

Caring for Canna

These plants are best adapted to hot summer climates. In areas where the soil temperatures reach 32 degrees Fahrenheit or lower, they are best when brought inside to store over winter. Cannas should be planted in springtime after the danger of frost has passed by, and do best in rich, loose soil. Rhizomes should be placed about 2-4 inches deep, 1.5 to 2 feet apart. In cold regions, start rhizomes indoors and transplant outdoors about a month and a half after the last frost has passed. Plant cannas in a space in the landscape that receives full to partial sun. The more sun they receive, the more they will grow and flower (six hours is ideal). They prefer a soil pH of between 6.0 and 7.0 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. After planting Cannas, mulch around their bases with organic mulching material to help retain soil moisture and suppress weed growth. Keep mulch away from the plant stems, as this can encourage an environment for root rot issues to take hold.

Water newly planted Cannas regularly as they establish a strong root system. They are moderately drought-tolerant at maturity and will only need water when the top two inches of soil is dry to the touch. Cut flowering stems to the ground after blooms expire. This will encourage rebloom and growth of new stems, which will continue to grow until into fall. Otherwise, the only pruning these plants need is to remove dead, damaged, diseased, or yellowing foliage. Clumps of plants should be divided every 3-4 years for the best health of root systems. For instructions on how to divide plants, see the Propagation section below. Fertilize yearly in early springtime with an application of about 2 inches of compost around the base of plants. This nutrient boost will be sufficient to carry the plant through its active growing season. In regions with cool winters (areas where the ground freezes in wintertime), underground storage roots should be dug up and stored in a cool, dark, dry place. They can be replaced in springtime once the ground warms. Cannas are considered long-lived perennials, persisting for decades in the garden if cared for correctly.

Caring for Canna in Containers
Canna flowers can be grown in containers, which is a situation that allows for gardeners in cooler regions to grow these tropical plants. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Canna plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top inch or two of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

Canna can be propagated either by dividing existing plants or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Canna Lily, follow the instructions below:

Propagating Canna by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
  2. Harvest your seeds. The seed pods on Canna plants are pretty easy to spot, they're large and have an interesting texture, left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them. Canna seeds are very round and have a tendency to roll away; make sure to use a tray or bowl to contain them.
  3. Canna seeds have a hard coating that protects them, but this coating also makes it a little difficult to get them to germinate. We can help the process along by scarifying them with sandpaper (or simply rubbing them against an abrasive surface). Do this with as many seeds as you can; they will probably not all sow, and the ones that do will be of varying characteristics. The more seeds you plant, the more chances you will have to get the resulting shrub you want. Place your seeds in lukewarm water for six hours. Viable seeds will sink to the bottom, and non-viable seeds will float to the top. You can discard any seeds that float.
  4. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  5. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
 
Propagating Canna by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost, and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every four to five years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:
  1. Gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the rhizome roots. Once you have worked it up out of the ground, lay it out.
  2. Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick rhizome section with two or three buds.
  3. Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divided rhizomes about an inch under the soil surface and water thoroughly.
  4. Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout.
Canna seed pods are green and will dry out and turn brown as they mature, eventually splitting open and dropping their seeds.
Canna seeds are hard, dark brown to black, and round. They have a very hard seed coat that must be scarified before sowing.

Problems and Pests

Take care when planting these flowers in the landscape, as they are considered to be invasive in some regions. Check with local authorities before planting. Cannas are largely free of pests and disease, though they can be susceptible to the following from time to time:
  • Leafrollers (Canna Leafroller Moth)
  • Slugs and Snails
  • Scale Insects
  • Mealybugs
  • Red Spider Mites
  • Canna Rust
For more information on these pests and diseases, including how to treat them, see the following links:
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Gallery

Cannas are popular hummingbird nectar sources.
Cannas produce beautiful foliage as well as flowers, and are welcome additions to any type of landscape.
Mexican Feather Grass and Coneflower are planted in front of a dark-leaved Canna cultivar in this mixed bed. 
This informal landscape uses Cannas to add height to a low bed surrounding a lawn area.
This dark-leaved Canna provides some interest to this cottage garden.
There are many different types of Canna with various flower and foliage colors.
Cannas grow well in containers, here planted alongside Creeping Jenny and Begonia.
Cannas add bright red color to this otherwise monotone evergreen bed.
Cannas can be planted near water features to add a tropical flair.
This desert landscape features Palms and Cannas.
Even when out of flower, these plants provide interest with their large, often colorful leaves.
This entryway is decorated with potted Cannas with various types of Ipomoea and Coleus.

Videos

All about growing Canna Lilies.
Why you should try Cannas in your garden.
How to divide and pot Canna rhizomes.
How to grow Cannas from seeds.

Resources

How to Grow and Care for Cannas
Canna Care Guide
Learn How to Plant, Care, and Grow Splendid Canna Lilies
Wikipedia: Canna (plant)
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 220, Canna