When Are Cannas Full Grown?

Life Cycle

• Cannas sprout from rhizomes in the spring or summer, depending on the species and cultivar. As the heat of the summer moves on, the plants unfurl their broad, graceful leaves, revealing tall, sturdy flower stalks that bloom in shades of red, orange, yellow, pink and cream. Most bloom in late summer to early fall. At that point, the flowers have reached their full growth. Once the cool weather of fall arrives, the blooms begin to fade and the foliage dies back to the ground, returning its nutrients to the rhizome where they will be stored until the spring.

Sizes

• At full growth, cannas range in size between 12 inches to more than 6 feet in height. "Intrigue" is a cultivar that can reach heights of 10 feet. It features salmon-pink flowers and attractive, green and burgundy foliage. Dwarf cannas include "Tropical Rose," a rose-colored beauty that reaches only 2 feet tall at full growth, and "Lucifer," a 2-foot-tall canna that has flame-colored blossoms of yellow and red framed by bright-green leaves.

Culture

• Cannas will not reach their full sizes if conditions are not right for growth. The flowers need exposure to full sunlight and rich, moist soil. They need 1 inch of water per week in the growing season, and many will thrive even in very wet conditions. A thin layer of mulch can help the soil retain moisture and stifle weed growth. Some cannas will bloom continuously if you deadhead, or pick off, the spent flowers.

Other Considerations

• The tallest varieties may need staking, depending on the cultivar and environment. For example, tall cannas planted in high-wind areas may benefit from additional support. Some cannas grow almost as wide as they are tall, so give them plenty of room to grow out as well as up.