Canna x generalis

Garden Canna is a herbaceous perennial and is most likely the hybrid of Canna indica and Canna glauca or Canna iridiflora. Currently, all Canna hybrids are included under the scientific name of Canna x generalis. The plants are very large and grow up to 6 feet tall. They will attract attention to any garden whether planted as an accent or in a mass planting. They have large colorful flowers and tropical appearing foliage. The foliage and flower color vary depending on the cultivar.

Garden Canna are hybrid plants found in tropical and subtropical regions of North and South America and India. The plant has been widely cultivated and has escaped old home sites. It can be found along roadsides, ponds, lakes, or streams.

The genus name, Canna, is from the Greek word "Kanna," which means reed-like.

Garden Canna prefers sunlight to light shade, soils with high organic matter, and slightly acidic pH. They grow best in moist, well-drained soils, but they can tolerate some standing water or drought once they are established. They have a high heat tolerance, but they are prone to wind damage. 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. In warm climates, the rhizomes may be left in the ground over the winter. In areas where the plant is not winter hardy, the rhizomes should be lifted from the ground for winter storage. They should be stored in peat or vermiculite in a cool dry space. The plant may be propagated by seeds, rhizomes, and division. 

The plant has fleshy rhizomes. The stems are 3-6 feet tall, glabrous, unbranched, and enveloped by leaf sheaths. The leaf color ranges from green, bronze, or variegated, depending on the cultivar. The flowers are 4 to 8 inches long and appear on the ends of the stem as racemes or panicles. The flowers bloom during the summer months, from July to August. Depending on the cultivar, the flower colors ranged from white, cream, yellow, orange, pink, coral, salmon, red, or bicolored. The fruit is a capsule that contains seeds.

Their striking and brightly colored flowers make them an excellent choice for a border grouping, and their tropical feel works well in pool-side landscaping.  

Diseases, Pest, and Other Problems:

Japanese Beetles may feed on the young leaves and flower buds. Aster yellows cause dull yellowing of the leaves that eventually turn brown. The disease is spread by aphids. Slugs and snails may also chew on the leaves. The plant is susceptible to leaf-rolling caterpillars. Canna mosaic virus causes pale yellow stripes on the leaves. Leaf spot, rust, and bacterial blight may be also be found. The rhizomes will rot in poorly drained soils. 

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

More information on Canna.