The Canna plant, often referred to by the misleading common name “Canna Lily,” is a striking addition to gardens and landscapes, instantly providing a dramatic, tropical aesthetic. This showy herbaceous perennial is prized for its large, bold foliage and vibrant, continuous blooms that last throughout the summer season. While it is a true perennial in warm climates, it is frequently cultivated as an annual in temperate regions. Its impressive height and architectural shape make it a popular choice for borders, containers, and mass plantings. The genus offers a wide range of cultivars, allowing gardeners to select plants with varying heights, leaf colors, and flower hues.
Classification and Origin
The Canna plant belongs to the genus Canna, which is the sole genus within the plant family Cannaceae. This classification places it within the order Zingiberales, making its closest relatives ginger, banana, and arrowroot plants. The name Canna is derived from the Latin word for a cane or reed, referencing the plant’s upright, tall growth habit.
All species within the genus are indigenous to the tropical and subtropical regions of the Americas, spanning from the southeastern United States down through South America. One species, Canna indica, was cultivated by indigenous populations for thousands of years. The plant’s starchy underground stems, or rhizomes, were an important food source.
Distinctive Physical Traits
The Canna plant is recognized by its remarkable foliage, featuring large, paddle-shaped leaves that can measure up to two feet long in some cultivars. These leaves emerge tightly rolled and unfurl to display colors ranging from solid green to deep bronze, maroon, or striking variegations. The plant’s upright “stalk” is not a true stem but a pseudostem, formed by the tightly overlapping bases of the leaves.
The flowers are equally distinctive, appearing in fiery colors such as bright red, orange, yellow, and pink. What appear to be petals are actually highly modified stamens, known as staminodes, which give the bloom its showy, asymmetrical shape. Beneath the soil, the plant grows from a rhizomatous rootstock, a swollen, horizontally creeping underground stem that serves as the primary storage unit. This rhizome structure classifies the Canna as a perennial.
Essential Growing Conditions
Successful cultivation of Canna plants relies on providing conditions that mimic their native tropical environment. The plants require full sun, ideally six to eight hours of direct sunlight, as this promotes the best flowering and maintains foliage vibrancy. While they can tolerate light shade, a lack of sun often results in fewer blooms and less vigorous growth.
The soil should be rich in organic matter, well-draining, and consistently moist. Cannas are heavy drinkers and thrive where they receive a generous supply of water, making them suitable for bog gardens or near water features. Good drainage is necessary to prevent the rhizomes from sitting in stagnant water, which can cause them to rot.
Canna plants flourish in high temperatures and humidity, performing well even in intense summer heat. They are not tolerant of cold temperatures; the foliage will die back when temperatures drop below 25 degrees Fahrenheit. Providing shelter from strong winds is beneficial, as the large leaves are susceptible to tearing.
Propagation and Seasonal Management
The most common method for increasing Canna plants is through the division of the rhizomes. This process involves separating the underground storage stems into sections, ensuring each piece retains at least one or two “eyes,” the growing points for new shoots. Rhizome division is typically performed in the spring before the growing season begins.
In regions with freezing winter temperatures, the Canna plant requires seasonal management to survive the cold. After the first hard frost causes the foliage to die back, the rhizomes must be “lifted,” or dug up, from the soil. The removed rhizomes should be allowed to dry slightly and then stored in a cool, dry location, such as a basement or garage, where temperatures remain between 45 and 50 degrees Fahrenheit. Storing the rhizomes in a medium like peat moss or vermiculite prevents them from drying out over the winter.