Canna "Bengal Tiger" has a striking green- and white-striped variegation on its foliage. Bright orange flowers tower above the foliage. Photo taken by Susan Conlon. >>>download photo

Submitted by Susan L. Conlon


Many gardeners in Tennessee are joining the "Tropical Punch" bandwagon by using tropical, or tropical-looking, plants in their gardens this summer. To join the group, consider using Canna (Canna sp.) in your own garden.

Canna adds a tropical flair to any garden with its bold texture, height, and colorful foliage. Valued for its foliage colors range from solid greens to purples and almost blacks to variegations combining a wide range of sizzling hot colors, including red, pink, yellow, and orange. Flower colors are also dazzling, ranging from white, red, orange, yellow, pink, and bicolors. Although Canna typically blooms from July to October, the foliage color variations are enough to stand on their own and keep your attention all season long.

Canna ranges in height from 2 to 6 feet tall and grows about as wide, depending on the cultivar. Dwarf and giant varieties are available.

Canna prefers full sun (if adequate moisture is provided) to part sun; it must get at least six hours of direct sunlight. Plants that do not bloom heavily may not be getting enough sunlight. Canna prefers a moist to wet soil and even can be submerged at the soil level in aquatic plantings and containers. Cannas are heavy feeders of fertilizer. If using an aquatic fertilizer, check for fertilizer rates before application.

Because of our moderately warm winters, Canna can remain in the ground during winter in many areas of Tennessee. For added winter protection, mulch plants. In areas of Tennessee with colder winters, rhizomes should be dug for overwintering indoors. Store rhizomes in sand or peat in a cool, dry location for the winter.

Canna is propagated by division, so consider asking a garden buddy who has Canna in their garden to see if they would like to do a plant swap. There are no serious pest or disease problems, but borers, slugs, and caterpillars may be a problem. Remove plants that have borer problems from your garden. Slug damage is generally kept to where slugs chew on the leaves and may make unsightly holes; this kind of damage is more of an aesthetic problem than life threatening to the plant.

To most prominently display your tropical specimen, plant Canna in masses, as a specimen plant, or in containers. Canna is also used quite effectively in sunken pots in water features, such as ponds, or in aquatic containers. Be sure to provide Canna with enough water throughout the summer to ensure it does not dry out.

With its variation of colors and big, bold foliage, Canna is a perfect complement to fine-textured plants, such as ornamental grasses, or even other tropical foliage plants, including Hardy Banana (Musa basjoo) or Elephant Ears (Colocasia, Alocasia, or Xanthosoma). Some varieties, particularly the heavy bloomers, can attract hummingbirds.

Some notable cultivars include:

"Australia" – Scarlet red flowers that play nicely off the burgundy to almost black foliage.

"Bengal Tiger" – Green- and white-striped foliage and brilliant orange flowers add a colorful tropical texture to the landscape. Can be grown in aquatic setting. Has a good clumping habit, co can be transplanted easily throughout the perennial border.

"Tropicanna" – Bright orange flowers are complemented by stunning red-, orange-, green-, and yellow-striped variegation on its foliage.

Submitted by Susan Conlon, volunteer coordinator for the UT Gardens and a graduate student in the University of Tennessee Department of Plant Sciences. Conlon works under the guidance of Dr. Susan Hamilton, director of the UT Gardens, which are located in Knoxville on Neyland Drive. The gardens are open to the public year round from dawn to dusk. More information is available at http://utgardens.tennessee.edu

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