Cannas have an interesting history
With their large, lush leaves and attractive flowers, cannas embrace the sun and warmth of summer. They are surprisingly easy to grow and have an interesting history. Many people call them canna lilies, however they are not a lily at all and are related to gingers and bananas instead. There are over 300 species of canna and their origins, like the tomato, potato and pepper are found in the Americas. The large, fleshy roots were once a source of starchy food for humans and animals alike and were probably one of the first domesticated plants. Along with food, they made rope, a crude paper, a purple dye and alcohol from the roots, stems, seeds and leaves of this versatile plant. Knowledge of so many of our ancient useful plants have been lost to history and it is important not to forget this information.
Growing cannas for butterflies, bees and hummingbirds
Cannas are great in the wildlife or pollinator garden. Butterflies and bees visit them regularly and hummingbirds adore them. Since they enjoy a sunny location as do many plants preferred by pollinators, plant them in your perennial beds along side other blooming plants and deadhead regularly to prolong the blooms. When the flower stalk fades, cut back to the next joint to promote another flush. Once that stem has ceased to bloom for the season, you can cut it to the ground, or simply remove the stalk back to the large attractive leaves. With such large leaves, cannas require quite a bit of water to maintain their lush appearance. They do well at the edges of ponds, however if planted in a drier spot, remember to give supplemental water every other day during the hottest weather.
Grow cannas in containers
Cannas make great container plants. Just be sure to give them a big enough pot. The tubers that you plant in the spring increase over the season quite a bit and can actually crack the side of a container if it is too small...ask me know I know this. However, containerized cannas are a great way for gardeners outside their cold hardiness zone to grow them. They can be started early indoors and moved outside as the weather warms. They need quite a bit of sun to have the best show, however the cooler northern summers don't seem to bother them much as long as they can bask in the sunshine and get plenty of water. Even gardeners in Alaska can grow cannas since the long summer days give the plants lots of light to grow. When frost threatens, cold winter gardeners cut the foliage back and bring the containers inside where the temperatures do not go over 50 degrees. An unheated garage with proper insulation or basement is perfect for canna pots. Once the tubers are completely dormant, tip them out of the pot and divide them. Replant a couple in the pot and save the rest or pass them along to a friend.
Grow cannas in the garden
The canna tuber is a thick, fleshy root with growth 'eyes' where the plant sprouts. The larger and more mature the root, the more eyes the tuber will have. Three to five eyes is an excellent size. When planting them outdoors, plant four to six inches deep and a couple feet apart in an area with moist, well-drained soil after danger of frost has passed.. Depending on whether your cannas are tall or dwarf, will determine on how far apart to plant them. The tall varieties need a bit more room than the dwarfs. There are so many options when it comes to cannas. The flower colors range from pink and cream through salmons, yellows and reds and even if they never bloomed, the foliage is wonderful. Dark bronze leaves, variegated stripes and different shades of green make for a wonderful display even if you just planted a canna bed. In zone 7 and warmer, cannas can be left in the ground all year (and even some cooler winter areas if mulched and sheltered) The taller varieties make a great back of the border plants and all of them will do great in ponds and bog gardens as long as the stems stay above the water line.
Few pests bother cannas. Slugs, snails and Japanese beetles are the commoner ones The slugs and snails enjoy the lush, juicy foliage and the beetles prefer the flowers. Good garden habits, such as removing dead foliage and debris where they hide will prevent the slugs and snails. Pick the Japanese beetles from the flowers and execute them in whatever manner you enjoy. The worst problem with cannas is the caterpillar called the canna leaf roller. This creature does exactly what its name implies, it uses the canna leaf as a rolled-up shelter while it pupates. Clipping the offending leaf works in most instances, however if the infestation is high, use Bt as a natural insecticide for caterpillars. It won't harm bees or adult butterflies.
Cannas are inexpensive and great for new gardeners
Whichever canna you plant, they are guaranteed to make a bold statement in your garden. The foliage gives a tropical feel to most any space and they pair well with many sun-loving plants and flowers. They grow quickly and fill empty spaces with a riot of color. New gardeners will find them easy and experienced hands know what a treat they are and use them in many spaces. The rhizomes are available from both specialized nurseries and big box stores. I've even seen them offered at my local fruit and vegetable stand. Many are quite inexpensive, so try a few and see what they can do for your garden.