Garden Gossip

With Ted Smith

Considering the monochromatic grey that greets the eye outside our windows at this time of year, one could be forgiven for searching out a bit of colour. As any avid gardener can tell you, there isn’t a plant out there that can give you a larger dose of that pure eye-dazzling colour than the gaudy canna lily.

Not only are canna lilies the ostentatious residents of the flower bed, they are also misnamed. More closely related to bananas and ginger, canna lilies are not actually true lilies. For this reason, many growers refer to them more simply as canna plants. There’s a lot to be said for reducing the confusion. Cannas belong to a group of plants collectively known as monocots. Perhaps the best known monocot is grass. This ties in with the name canna which is derived from the Latin for reed or cane (which are also monocots). Unlike their more demure relatives, cannas love to announce their presence to the world. Bright lurid flowers ranging from yellow through orange to red are the most commonly seen. Purple cannas are also now available and speckled or multi-hued flowers are also quite common. One of the earliest written records of a canna refers to yellow flowers covered in bright red spots. While the leaves of a canna are generally a little more sedate, newer cultivars are available with purple leaves as well as leaves striped with vibrant colours including purples and oranges.

Tropical and sub-tropical plants, cannas were naturally distributed between the extreme southern United States and central South America. Cannas are so comfortable in tropical climates that they have become quite problematic in some tropical countries around the world where they have escaped cultivation and become naturalized. Once they become entrenched in a new tropical home, cannas are very difficult to eradicate. We won’t have that problem here.

One little known fact about cannas is that they were grown as a food crop long before Europeans arrived in the Americas. Cannas are, in fact, one of the oldest cultivated crops of the Americas. Both the flowers and the roots are considered edibles. The flowers are more decorative and are said to have a refreshing lettuce-like texture and flavour. The roots are the more traditional food source. Cannas grow from very large fibrous tubers that are quite high in starches. This allowed them to fill a critical niche in the diets of humans who were transitioning from nomadic to agrarian lifestyles. For those of you who may now consider trying this new gourmet treat, be aware that canna roots are very fibrous. Very. The flavour is said to be excellent but at the end of every bite is a mouthful of fibres needing to be disposed of. Interestingly, those fibres also occur in the leaves and are used in some areas in paper making. Also, don’t mistake a canna lily for the similar sounding cala lily which is poisonous. 

Because of their tropical roots, you can likely deduce what cannas will need to grow happily in a northern garden. The first is ample moisture. Cannas do not like to dry out but they also do not enjoy wet feet. They should be grown in rich fertile soil that is kept evenly moist. A good deep layer of organic mulch will greatly reduce the need for constant watering during dry periods. Cannas also love sun and warmth. They should be planted out after all danger of frost has passed although the roots will survive a light frost and re-grow. Protect them from chilling and shredding winds. Tall plants with very large leaves, cannas do not tolerate high winds very well. Instead, cannas do well in micro-climates such as can be found in alcoves or against south facing walls and fences. If your cannas must be exposed to wind, consider staking them.

Most gardeners buy their first canna already potted and growing. This is the surest way to get started. If you would like a little more variety to choose from, many different cannas are available through mail order and will arrive as dormant roots that look quite similar to dahlias. Immediately pot them, water them and put them in a warm area. They can be grown indoors until outdoor temperatures become warm. If you’d like a real challenge, try growing cannas from seeds. Canna seeds are large, shiny, black marble-looking things with an exceptionally hard exterior. The shell around a canna seed is so impermeable that seeds can lay dormant for many years while remaining viable. Starting canna seeds requires nicking them with a sharp blade or rubbing through the shell with sandpaper. Then the seeds should be soaked for a day or two in warm water before being planted. After this they will still germinate erratically even in their preferred warm moist environment. Starting cannas from seed is a great challenge for the gardener who feels like there just aren’t any more left!