Cannas: Exotic and colorful summer-blooming bulbs

Gardeners often think of bulbs as things we plant in the fall with the expectation of blooms early the following spring. Daffodils, tulips, hyacinth, and crocus are especially beloved spring-flowering bulbs. While these all have a place in our gardens, many summer-blooming bulbs exist as well and provide colorful blooms during the hot months. One of these that many gardeners know is the Canna Lily.

Canna lilies are native to tropical regions in Africa as well as Central and South America. They have large, paddle-shaped leaves that may be as much as 2 feet long and 12 inches wide. These leaves are typically green, but many cultivars have red, purple, yellow, or variegated leaves that add ornamental interest. Cannas are prized mainly for their flowers, however, which appear atop tall stalks in mid-summer and often last until frost in fall. Considering the tall flower stalk, plants may reach heights of anywhere between 2 to 8 feet in height. Flowers come in a variety of colors, from yellow to red to pink, peach, salmon, orange, to cream. Some gardeners find the common combination of yellow or red flowers with solid green leaves to be somewhat bland, but the wide variety of bloom colors and leaf colors and patterns quickly makes it possible to find more interesting combinations.

One of the most popular cultivars is ‘Bengal Tiger,’ prized for its striped yellow and green leaves, and with orange flowers growing to a height of 3 to 4 feet tall. Similar, but slightly less common, are ‘Red Tiger’ and ‘White Tiger,’ which both also feature striped foliage, but have red and white flowers, respectively, rather than orange. Tropicanna ‘Phasion’ is another popular cultivar, with 6 foot tall orange flower stalks atop plants with green leaves with red and yellow streaks or blotches. ‘Black Knight’ has red flowers, with smoky purple-burgundy leaves.

Top left: 'Bengal Tiger' leaves. Top right: 'Tropicana Phasion.' Middle left: 'White Tiger' Canna. Bottom left: 'Red Tiger' flower. Bottom right: 'Black Knight.'

Regardless of the cultivar that you find most visually appealing, cannas will need essentially the same care. While they tolerate a fairly wide range of soil types and can grow in both full sun and partial shade, they are at their best when grown in moist, well-drained soils and full sun. Provided the soil drains adequately, they can actually tolerate very wet conditions for temporary periods, making them suitable for situations such as rain gardens or around ponds or pools.

Cannas spread by rhizomes, an underground stem, and they should be divided periodically to be kept under control. Cut the plants down in winter and remove the old foliage to prevent insect problems, as they often overwinter in dead foliage. Though many cannas are quite hardy, they are a tropical plant and may sometimes suffer injury during cold winters. Many gardeners choose to dig up the rhizomes and store them indoors. This may not always be necessary, but if you choose to do so, keep the rhizomes in a dry and dark place until replanting in the spring.

Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705.