Cannas have style, looks, star power
JACKSON, MISS. — There's not a canna named for Dolly Parton, but there should be. Both stand out, no matter what's around them: voluptuous and colorful from top to bottom. Both are incredibly adorned, tending toward bright colors neatly arranged, with not a hair or petal out of place. Even if their style doesn't match yours, their boldness will make you smile.
Perhaps it's because cannas display such a carefree good spirit that gardeners love them in containers, flower beds, and borders. Or maybe it's because they're among the easiest plants to grow. They'll be content in average soil and with half a day of sun, but put on their biggest leaves and blossoms in better soil and full sun.
Cannas that are several years old are somewhat drought-tolerant, forgiving forgetful gardeners by storing water in their rhizomes (the thick underground portion from which the roots and stem grow). The plants don't perform well in very heavy, constantly wet soils, but can adapt to most moisture conditions when planted in lighter soils, which is why they're often planted beside ponds. Like a favorite overstuffed chair, they seem to get comfortable anywhere you put them.
Until recently, cannas were regarded as a guilty pleasure for many gardeners because they were seen as common and utilitarian. The earliest introductions escaped cultivation in the southeastern United States before 1900 and made themselves at home in many marshy areas. (No one knew it at the time, but cannas have since been shown to be one of the most efficient filters of organic water pollutants, such as manure or sewage.)
In the homebuilding boom following World War II, homeowners planted cannas to mask utility boxes and trash cans, their fast-growing, bananalike leaves and bulbous flower heads consigned to alleys across the South.
But in recent years the canna's reputation has certainly changed. New introductions, including Tropicanna and Gold Tropicanna - which emphasize showy striped leaves instead of the flowers - have caused huge changes in the image and appeal of the entire canna family. Instead of being consigned to alleys, dramatic new canna cultivars are now showing up in trendy designer gardens.
Tropicanna's leaves begin as burgundy-striped and quickly take on shades of red, pink, yellow, gold, and deep green against the bright chartreuse background and center rib of each leaf; its flowers are tangerine orange.
It burst into American gardens in 1997, and was "so dazzling, it reawakened interest in cannas languishing since the Victorian era," says Sally Ferguson, director of the Netherlands Bulb Information Center. "Cannas are very popular, and it's because of those iridescent, shimmering striped leaves. They just glow when backlit by the sun."
Tropicanna Gold's foliage starts and stays distinctively striped in gold and green below spikes of lilylike, orange flowers with yellow markings and edges. "Its effect in the landscape is clean and crisp in line and flower," says Ms. Ferguson. "Tropicanna Gold is a true performer in the garden."
Both Tropicannas are classified as medium height, reaching four feet tall in the first year, a bit taller in subsequent years in areas where rhizomes can be left in the ground over the winter.
Bengal Tiger - with fine green stripes on lemon yellow leaves and orange flowers - reaches five feet or a bit higher. Orange Beauty and Red Dazzler pass six feet, their huge clumps providing excellent summer shade for small wildlife.
Smaller and well adapted to containers and window boxes, dwarf cannas mature between two and three feet tall. Lucifer boasts bright red flowers with bold yellow edges, while petite Princess Di is subtle - for a canna - with creamy pink blooms.
Whether it's solid green - or displays wild stripes in combinations of green, copper, yellow, and red - canna foliage feels like banana leaves and looks like broadswords.
From the leaves rise tall flower spikes, from which narrow or wide petals spill out in clusters and are followed by hard, round "shot" or seeds. The spikes with seed are attractive in their own right, or gardeners may remove them for use in flower arrangements.
"I grow cannas because they're easy and so colorful," says Leon Hill, a home gardener in Hinds County, Miss., "and they grow fast."
Indeed, Mr. Hill has more than 5,000 cannas at his home. "I recycle them from sites where old houses have been torn down," he says, a testimony of the easy care and longevity of the canna plant.
If you have a choice, place cannas on the hottest corner of your garden - south and west exposures - so they grow faster, he suggests. Plant canna rhizomes two to three inches deep in soil to which you've added compost or other organic matter.
When transplanting a canna from a container, plant it the same depth it was growing before. If the soil is moist, the rhizome will multiply and form several more by autumn's end. (See directions on winter care at right.)
During the growing season, fertilize regularly with a fertilizer made for flowering plants. If cannas are hungry, they display poor color, ragged leaves, and few (and sometimes distorted) flowers.
During the summer, after each canna flowers, cut its stem down to the ground, Hill advises. More will follow, often two for each one you cut down. That produces more flowers and a larger clump. And with today's cannas, more and bigger are definitely the way to go.
While cannas can be grown in USDA hardiness Zones 3 to 11, the underground rhizomes (fleshy root system) won't survive outdoors over winter in Zones 3 to 6. Here's what to do:
• Zones 3 to 6 (cold winters) - When leaves begin to go dormant in the fall, cut them back, leaving six inches on each stem. Then dig up the rhizomes, along with some roots and soil, shake them off, and put in a dry, well-ventilated place out of direct sun for a few days. If humidity is high in your area, dust the rhizomes with sulphur before storing. Put them in ventilated mesh bags, the kind in which onions are sold. Be sure to use enough peat moss, cedar shavings, or sawdust around the rhizomes to keep them from touching one another, which can contribute to rot. Put the bags in a dry place where temperatures remain above freezing (45 to 50 degrees F. is ideal).
• Zones 7 to 11 (mild winters) - Let the cannas go dormant in late fall and as the plants begin to turn brown, cut them down to the ground. Remove all the old plant parts and apply fresh mulch for the winter. (In Zone 7, pile two to three inches of mulch over the rhizome area.) Cannas planted in containers are more susceptible to cold than those growing in the ground. Those in small containers and in colder regions are more likely to be damaged by low temperatures than cannas in large pots and areas with milder winters. If you have any doubts about whether they will survive the cold, put the containers in a garage or shed over winter after cutting the plants back to soil level, so the rhizomes don't freeze or rot.