• Cannas are large and sometimes varigated.Canna Leaves image by Jennifer Grush from Fotolia.com
  
  Cannas, or canna lilies, are large, tropical plants prized for their spectacular flowers and big, colorful leaves. Related to the banana plant, cannas produce large, flat leaves that unfurl from stems. Flower colors are typically red, orange or yellow; some species have maroon, bronze or variegated leaves. Cannas are annuals in colder climates, but perennials in the Deep South. Cannas are easy-to-grow, and produce dramatic results, once you learn the basics of proper cultivation.
  
  

Planting

• Gardeners grow cannas from rhizomes: fleshy stems that send out roots and shoots. Plant rhizomes directly in the ground after all danger of frost is past. In colder climates, start rhizomes in pots indoors in February, and transplant outdoors when the ground warms in the spring. Select a warm, sunny location to plant the rhizomes. Cannas can tolerate partial shade, but thrive in full sun. Lay rhizomes horizontally in the ground and plant about 2 to 3 inches deep. Space taller cannas about 18 inches apart and dwarf varieties about 12 inches apart, advises the University of Florida IFAS Extension.
  
  

Soil and Fertilizer

• Cannas prefer moist, well-drained soil that is heavy in organic content. The Alabama Cooperative Extension recommends amending soil with 2 to 4 inches of organic material such as rotted manure, compost or grass clippings. Fertilize cannas in the spring, and continue applying fertilizer monthly throughout the growing season.
  
  

Pruning

• Cannas produce colorful orange, red or yellow flowers.orange canna lily blossom image by Jack Prichett from Fotolia.com
  
  To encourage vigorous blooming, remove shoots once the flowers have faded. According to the University of Florida Extension, if you do not remove spent shoots, the plant will channel its nutrition toward developing seedpods, not growing new flowers. Removing spent shoots encourages new flowers, and extends the blooming time. Once the plant has finished blooming for the season, cut all shoots and leaves back to ground level.
  
  

Fungus

• Cannas are susceptible to a leaf fungus called canna rust, or frangipani rust, warns the Alabama Cooperative Extension. This fungus causes yellow or orange spots on stems and leaves. Canna rust is most often a problem in warm southern climates where humidity is high. Remove infected leaves and stems immediately, or the disease will spread to the flowers. Always keep dead leaves raked up from the ground around the plant.
  
  

Insects

• The larva of the leaf roller or Brazilian leafhopper is the main pest affecting cannas. Leaf roller caterpillars are often hard to see because they roll or fold the leaf around themselves as they devour the plant. Over time, leaves appear shredded and you may see brown and silky webbing. If you don't remove the caterpillars, the plant will be unable to produce new leaves or blooms. In addition, remove infected leaves immediately. If severe infestations require insecticides, the Alabama Cooperative Extension recommends using a systemic fertilizer and insecticide combination, Sevin dust or insecticide soap. In addition, the microbial insecticide Bacillus thuringiensis is effective in controlling the leaf roller. This bacterium is non-toxic to birds and mammals, but a natural enemy of the leaf roller.