More Info on Cannas
Thanks to their large, strapping, banana-tree-like leaves and stunning, brightly coloured flowers on tall, sturdy stems, cannas add bold drama to Uk gardens.
Canna blooms, which are irresistible to butterflies and hummingbirds, come in variations of cream, yellow, pink, orange, salmon or red and can be striped, streaked or spotted. They are low-maintenance plants that will grow and multiply quickly and flower continuously from midsummer until autumn.
Though cannas may be grown from seed, they are more often propagated from rhizomes (thick, elongated underground stems). In milder areas, where temperatures never go below freezing, cannas can be left in the ground year-round. For most of The Uk, however, they should be treated as annuals or tender perennials that must be overwintered until March, at which time plantings should be started indoors.
Native to southern Asia and tropical areas of Central America , cannas are the only genus in the Cannaceae family. Their name comes from the Greek word kanna , which means reed-like plant. Often called canna lilies, they are actually not related to the lily family, but are so-named because of their large, exotic-looking flowers.
There are more than 50 species and over 100 canna hybrids available today. Varieties are usually categorized by height as short (under 90 centimetres tall), medium (90 to 180 centimetres) or tall (more than 180 centimetres).
Growing Tips
Choose rhizomes that are thick (five or more centimetres) and firm and have at least one eye (growing point or crown).
Cannas won't tolerate dry conditions, so water at least once a week. When cannas need water, their leaves begin to curl slightly.
Choose a site where they will have at least four hours of full sun each day. The more water, fertilizer and bright sunlight they get, the bigger they will grow.
Cannas do best in rich, moist soil with lots of added organic matter. Plant rhizomes 12 to 15 centimetres deep, laying them horizontally with eyes pointing up, then cover with about five centimetres of soil.
Good air circulation is important, so space rhizomes 45 to 60 centimetres apart. Small or dwarf cultivars may be planted as close as 30 centimetres apart.
Feed every two weeks during active growth with all-purpose, water soluble (20-20-20) fertilizer or once a month with granular bulb fertilizer.
Deadhead to promote continuous flowering, being careful not to destroy developing buds.
Because they're sturdy, there's no need to support canna stems, but they may need protection in windy locations to prevent leaves from becoming tattered.
Cannas may be attacked by slugs or snails. The safest way to combat these pests is to pick them off by hand. Be extra diligent when the plant is young and more susceptible to these uninvited guests.
In From The Cold
Overwintering should begin after the first autumn frost has blackened the foliage or the foliage begins to wither. Cut stems back to 10 to 15 centimetres. Gently dig up each clump of roots, turn them over and allow them to dry for a few hours. Don't wash. Soil left on the rhizomes will help to keep them from drying out. Store clumps in barely moist, sterile sand, peat moss, or vermiculite in a cool, dark location. Ideally, place them on shelves or racks, or hang them in mesh bags so that air can circulate around the rhizomes. Don't let the planting mix freeze or dry out during storage. The medium should remain moist but not wet, or the rhizomes will rot.
In spring, about six to eight weeks before the average date of the last frost in your area, remove the rhizomes from storage, split them into sections using a sharp knife, and make sure that each section has at least one good root and one good eye. Remove any damaged foliage and rotten plant pieces. Let the cut surface dry out for at least 24 hours before planting to prevent fungus. Plant each piece in a separate container of soil or planting mix until it's well rooted. Begin a regular watering and monthly feeding program with a 10-10-10 fertilizer. When all risk of frost has passed, transplant the young plants into the garden. (They may be transplanted as late as June, but then will only produce foliage, not flowers.)
Growing Cannas Pointers
Here are a few pointers that we consider essential for successful canna growing:
It's a good idea to harden off plants that were started indoors for about a week before planting them out, just to be on the safe side. But make sure to put them outdoors only when daytime temperatures are 15°C or higher.
Remove all buds before planting out so the plant can concentrate on root growth rather than producing flowers.
Plant cannas in the garden 2.5 to five centimetres below soil level so the roots can get to water.
After an initial watering, let them dry out a bit to motivate the roots to spread out and find water. If you're sitting in the garden and people keep bringing you glasses of water, you won't budge from your chair,.
If your cannas don't start reaching for the sky, you're doing something wrong,. Usually it's not enough water. Good Luck!
