How to Overwinter Canna Plants

Overwintering Cannas

• 1

  Wait until the first frosts have killed the leaves of the canna. Cut the plant back to 6 inches from the ground, using a shovel or a garden fork to dig the rhizome.

• 2

  Brush the soil off of the rhizome, but do not rinse it. Keep it intact, as any wound provides an opportunity for rot. Dry the rhizome for three to seven days. Turn it if necessary to expose all sides to the air.

• 3

  Fill the bottom of a cardboard box with 1 to 2 inches of peat moss, sand or perlite. Place the canna rhizome on top and cover with an equally thick layer of the material used on the bottom of the box. The medium should be slightly moist so the canna does not get overly dry during storage. If you are storing more than one rhizome, do not allow them to touch in the box. Keep the top of the box open once the rhizomes are buried.

• 4

  Place the box in a cool, dry location such as a minimally heated basement. The ideal temperature for storage is 45 to 50 degrees Fahrenheit. Check the rhizomes periodically throughout the winter to make sure that they have not begun to rot, or, alternatively, become dessicated. Soft spots are a sign of rot, whereas wrinkling of the outer flesh indicates the rhizome has become too dry. If the latter occurs, use a spray bottle to lightly mist the storage medium with water before covering the rhizomes again.

• 5

  Leave the box in its location until late February or March, at which point the cannas can be divided, potted and grown indoors to give them a head start on the growing season. Otherwise, wait until the outside soil temperature has warmed to at least 60 degrees Fahrenheit before planting the cannas directly in the ground. Cannas do best in warm conditions, so avoid planting them too early in spring, when the soil may be cold and wet.