How to care for Canna plants throughout the growing season. Planting Canna lily bulbs, rhizomes, and seeds. Buy red, yellow, and orange Canna lilies including 'Bengal Tiger' and 'Picasso'.
Canna lilies growing inside the conservatory at Longwood Gardens.
Add tropical splendor to temperate zone gardens by planting Canna lilies. Cannas are most often used in tropical bedding designs where their bold leaves and showy blooms delight the eye all summer. The shorter varieties also make wonderful container plants.
Canna generalis is the result of crossing Canna indica with other species. These tall and dwarf hybrids have also been crossed with each other. Their prodigy are also classified as Canna X generalis.
C. indica has long been cultivated for its fat, starchy, edible rhizomes which are used to make noodles and other foods in Asia. The thinner rhizomes of the other species are edible as well, but before you decide to add Cannas to your vegetable plot, let me warn you:
The rhizomes are less nutritious than Irish potatoes, and they have the curious, albeit useful, habit of removing toxins from the soil.
Where do those toxins end up?
You guessed it, inside the plant.
Where you need to remove heavy metals from the soil, use Canna plants as your clean up crew. If you're looking for a side dish, stick to potatoes.
Today, there are hundreds of named cultivars ranging from two to more than eight feet in height. These plants display a multiplicity of leaf colors and patterns and bloom in colors ranging from yellow and orange to pink and red.
Tiny, testing some yellow blooms for scent.
Most Canna flowers are scentless, but some of the newest hybrids are fragrant.
The flowers of Canna hybrids are large and most often boldly colored. The blooms of some single flowered types resemble iris flowers. Others look more like gladiolus or Cattleya orchid blooms. Some cultivars feature ruffled or double flowers.
Canna species bear smaller blooms than the showy hybrids. The flowers of C. iridifflora are red-pink and pendant.
Clusters of elongated flower buds emerge from the sheathed tips of the canes beginning in early summer. The open blooms are held just above the striking green, red, or variegated foliage. Deadhead spent flowers to keep the clumps neat and productive.
Tall red Canna lilies growing behind variegated croton plants.
Dark Canna leaves punctuate a bed of pink and white dahlias in a city park.
Plant tubers three inches deep into the soil and space them 18-24 inches apart. They are most striking when planted in large numbers, so it won't pay you to skimp when ordering tubers.
If you want to be thrifty, buy the seed instead and start them a little earlier.
Canna plants require a minimum of six hours of sunlight per day to bloom well. They are heavy feeders that like a lot of organic compost mixed into their soil. They prefer a moist to wet soil during the summer and can be used to good effect in boggy areas.
There is a property in my neighborhood that slopes down sharply to the street. The street frontage tends to collect water during the rainy season. The householder has made brilliant use of this area by planting Canna and bananas along this strip.
Talk about taking a lemon and making lemonade!
Like bananas, Cannas can take all the moisture you can throw at them in the heat of summer, but they don't like to be wet during the winter. If you don't have a bog to plant them in, mulching will help to conserve water.
Canna rhizomes are hardy in the ground to zone 7b. In colder areas, they will have to be lifted and stored over the winter. This is also the best way to preserve the tubers if winters are wet where you live.
There is one major pest that plagues the Canna lily.
Canna leaf rollers.
These are caterpillars that roll themselves up in the plant's leaves and eat them. They are the reason I have given up growing Canna. I got tired of fighting these nasty worms.
They are more of a problem in some areas than in others. In fact, some gardeners have never seen one on their plants. Some people only see a few here and there and can just hand pick them off. I, of course, had tons of them. This may be because their main munching ground is the American south where I choose to make my home.
If you need to control them with a spray, Bacillus Thuringiensis is a good organic control.
If you're not a "green" gardener and feel then chemical warfare is in order, the systemic insecticide Orthene will work as well. Bayer Advanced Garden 2-in-1 Systemic Rose & Flower Care will feed and protect your Canna plants from leaf miners at the same time.