The beautiful canna lily, Canna indica, is a perennial favorite in the garden. This plant provides an excellent show of color with its large, dramatic blooms that are easy to grow.
If you want to know how to grow canna lilies and get them ready for planting, read on!
What Are Canna Lilies?
Cannas are the only genus of flowering plants that belong to the Cannaceae family. These plants aren’t actually true lilies, as most people believe, but are instead more closely related to plants such as ginger, bananas, arrowroots, birds of paradise, and heliconias.
With their large, attractive foliage, they are popular garden plants. They are often grown as starches for food (both for animals and humans) and are native to the tropics.
Despite being native to the tropics, though, these flowers are often grown in more temperate areas. They can be grown as houseplants but there are numerous cultivars that have been developed to grow in climates where at least six to eight hours per day of sunlight is attainable.
The most common variety of canna lily that we grow in our gardens is Canna indica, sometimes called achira in Latin America. There are also Canna glauca varieties as well as combinations of the two.
These flowers are native to tropical and subtropical regions of the Americas and have become naturalized in most places. Though most often grown as ornamental plants, either directly in the garden or in pots, they also have many uses in agriculture, jewelry-making, musical instruments, and more. In some parts of India, canna lilies are even fermented to produce alcohol!
A tall plant with tropical-like foliage, the canna lily produces large flowers similar to those of the iris. The plant is considered one of the most low-maintenance and easy to grow, offering attractive and vibrant colors in the garden. Both flower and foliage colors for this plant vary depending on the specific cultivar.
Growing Canna Lilies
These flowers grow best in full sun with moderate amounts of water, ideally in rich or sandy soil. The plants are best grown from perennial rhizomes but can also be grown as annuals.
Wherever you choose to plant your canna lilies, it’s a good idea to make sure it is relatively sheltered. When it gets extremely windy, the high winds can tear the leaves and flower petals from the plant – so consider planting your flowers against the side of a house or in another sheltered location.
Again, canna lilies are sensitive to frost and will rot if they aren’t protected during cold weather. If your winter temperatures regularly drop below 14 degrees Fahrenheit, you can dig up the rhizomes or cover them with a thick layer of mulch.
Because of these specific requirements, these plants are typically grown as annuals in cool environments. They love lots of heat and can tolerate partial shade but only if it’s warm enough.
How to Plant Canna Lily
You can propagate cannas by division or seed, though division is arguably the easiest.
Growing with rhizomes is the best way to cultivate these plants. When planting outdoors, make sure the danger of frost has passed. You Can plant groups about a foot or two apart.
To plant by division, start by cutting your rhizome into sections with each containing at least three eyes (these look like red dots). Then, to plant the rhizomes, insert them horizontally into the soil with the eyes facing up. cover each one with about three to six inches of soil, then water well and apply mulch to retain moisture.
Consider planting your canna lilies where they will have the most visual impact during the height of summer. Most cultivars are tall and therefore are best positioned at the back of a raised bed, but that’s not always the case. Full sun is ideal, though, of course.
Canna lilies like a lot of heat, growing well even when temperatures creep into the high 90s! These plants are root-hardy perennials in places where the ground does not freeze.
These kinds of flowers prefer soil that is rich and well-draining, ideally with a pH of around 6.5
Caring for Canna Lilies
Here are some tips to help you care for your canna lilies for long-lasting color.
Keep your flowers moist, especially until they are established. At least one to two inches of water per week is ideal to keep the plants looking their best.
Be sure to do some research into how much water is needed by your specific cultivar, though. There are some cannas that prefer to be dry while others grow best when partially submerged in shallow water!
Monthly feeding is necessary for most canna cultivars. You will want to use a fertilizer that is higher in phosphate to improve the plant’s ability to bloom.
These flowers are heavy feeders and need lots of compost or other organic fertilizer to keep the plants looking good. If your plant starts to look a bit tattered or ratty as the summer wears on, it’s time to fertilize. Know that it is very difficult to over-fertilize a canna lily, especially if you are using an organic fertilizer.
Pests and Diseases
For the most part, canna lilies remain free from pests and diseases, which is just one reason why these plants are so popular for gardeners.
One disease to watch out for is canna rust, a fungal disease that causes orange spots to appear on the leaves of the plant. Generally, this is caused by soil that is too wet, so it’s important to follow the guidelines for watering and planting listed above.
Occasionally, your plants may also fall prey to various viruses, most of which are specific to the canna genus. These are usually mild, rarely causing death but instead resulting in stunted growth or discolored leaves.
Every now and then, canna lilies might fall victim to a fungal disease called botrytis. This is most common in humid conditions and again, preventing overwatering is your first line of defense in treating this disease. You can also remove old flowers to prevent mold from spreading to new plants.
As for pests, keep an eye out for snails, slugs, and Japanese beetles. All damage plants by chewing large holes in the leaves (or by feasting on their flowers).
Typically, you can reverse or prevent these problems by limiting the use of chemical fertilizers and by amending the soil with lots of high-quality compost before you plant. The healthier your plants are, the more resilient they will be when it comes to fending off pest attacks.
Another pest to keep an eye out for is the canna leaf-roller, typically found in the southern portions of the United States. This pest, in moth form, lays eggs in the stalk’s buds. The caterpillars then use a sticky bit of webbing to stop the leaf from unfurling, feeding inside the rolled-up area, and causing serious damage to the plant.
Keep an eye out for these pests when canna lilies are the most vulnerable, typically in the early spring. Open the leaves and remove the caterpillars if you notice them upon inspection of your plants. You can use an insecticide like Bacillus thuringiensis but this is often not necessary unless pest populations are extremely high.
Growing Canna Lilies in Containers
You can even grow canna lilies in containers! If you do this, make sure you choose a pot that is large. This will give your plants all the room they need to grow.
Bear in mind that canna lilies are large plants and will only get bigger. If they become pot-bound, they will lose their vigor. Your plants should be planted in high-quality potting soil and be watered once or twice a day.
Because plants grown in containers also leach nutrients more quickly than those grown in the ground, remember that more frequent fertilizing will be necessary, too. Aim to fertilize about twice as often, using a water-soluble or slow-release granular fertilizer.
Other Growing Tips
One final tip for growing canna lilies? Make sure you dig up and store the rhizomes in the fall if you live in a cooler area.
If you don’t do this, your other option is to let the plants overwinter in pots so that they can grow throughout the winter months. Once the weather warms up, you can replant them in the garden or just move them back outdoors. You may also choose to divide the plant at this time, if desired.
Pruning is not necessary with canna lilies but again, if your plant is looking a bit tattered, just cut the plants to the ground, add water and fertilizer, and wait for them to recover. This can be done at any time of the year, even in midsummer.
Common Types of Cannas
Almost all cannas grown by gardeners are cultivars, with about 20 species existing in the wild form. Cannas were extremely popular in the Victorian days as garden plants and there are many cultivars from this period that are still available.
Cannas get their name from the Greek word “kanna” and the Celtic “cana,” which refer to “a reed-like plant” and are closely related to the musical word “canon.”
The most common wild species of canna lilies you will find include:
- Canna bangii
- C. flaccida
- C. glauca (the most common variety used in modern cultivars, since it can tolerate wet conditions a bit better than others)
- C. indica (the most popular agricultural variety)
- C. iridiflora
- C. jaegeriana
- C. liliiflora
- C. paniculata
- C. pedunculata
- C. tuerckheimii
- C. amabilis
- C. coccinea
- C. compacta
- C. discolor
- C. jacobini flora
- C. patens
- C. pluri tuberosa
- C. speciosa
Of these, there are a few cultivars that are considered to be the most popular among home gardeners.
Canna indica ‘Red Stripe’ is one such example. This plant has 8’ tall stalks that boast nearly two-foot-long leaves, typically in purple, with dramatic green patterns between the veins. The flowers are small but a bright, noticeable red.
Another common variety is Canna iridiflora, or Peruvian canna. This species has been used almost exclusively as a parent plant in creating most modern canna hybrids. It’s extremely tall, growing up to sixteen feet in height, with pink pendulous flowers that appear later in the season.
Some other canna lily cultivars to consider for your garden include:
- ‘Apricot Dream’
- ‘Bengal Tiger”
- ‘Pink Sunburst’
- ‘Thai Rainbow’
- ‘Kansas City’
There are hundreds of options out there, so be sure to keep looking until you find the one that’s perfect for your needs.
*image by AekPN/depositphotos