Canna glauca

Water canna is a herbaceous perennial in the canna family (Cannaceae) native to the wetlands of tropical America. The name comes from the Greek word kanna meaning "reed like".  

It grows best in moist, organically rich, well-drained soils in full sun or partial shade (it cannot grow in full shade). They grow 4-6’ tall with narrow, blue-green leaves (up to 18” long) and small pale-yellow flowers.  In warmer zones, the rhizomes may be left in the soil to over winter.  After the first frost, cut the foliage down to the ground and cover with available mulch.  In colder zones, dig up the rhizomes and bring inside and store them in peat or vermiculite in a cool dry space with temperatures between 45 - 50 degrees.  The rhizomes should be planted after the last spring frost. It is best to plant the rhizomes at least 5 inches deep and 12 inches apart.  Spent flowers should be removed to encourage continued flowering through the summer months.  Plants in containers can be left in their containers once brought inside.

As one of its common names implies, Water canna can be grown in water.  These aquatic cannas can be grown in shallow still or slow-moving water, up to 6 inches during the summer.  If growing them in water, they should be introduced to water gradually.  

The showy yellow flowers appear in clusters at the end of stems and bloom most of the summer. The large narrow leaves clasp the stem and provide ornamental interest.

Use the plant to provide color around ponds and bogs in groups and rain and water gardens

Insects, Diseases, and Other Plant Problems:  Keep in mind that rhizomes may rot in poorly drained wet soils and the plants are susceptible to damage from aster yellows. Japanese beetles, leaf-rolling caterpillars, slugs and snails that are known to chew on the foliage. 

VIDEO Created by Elisabeth Meyer for "Edibles, Bulbs, and Houseplants," a plant identification course developed in partnership with Longwood Gardens.   

More information on Canna.