The Canna ‘Tropicanna’, also known as Canna ‘Phasion’, is a tropical perennial prized more for its stunning foliage than its flowers. It grows rapidly to heights of four to six feet in a single season, introducing a bold, exotic aesthetic to the garden. Its paddle-shaped leaves display vibrant stripes of orange, red, purple, and deep green. These striking colors are complemented by vivid, burnt orange to salmon-colored orchid-like flowers, which bloom profusely from mid-summer until the first frost. The intense hues and large scale make the Tropicanna Canna Lily a sought-after accent plant for garden beds and large decorative containers.
Establishing the Tropicanna Canna Lily
Successful growth requires proper site selection, as the Tropicanna Canna Lily is a sun-loving plant that requires maximum light to achieve its signature coloration. Planting in a location that receives a minimum of six to eight hours of direct sunlight each day is necessary to ensure the foliage develops its full, vibrant spectrum of stripes. Without sufficient sun exposure, the leaves tend to revert to a less colorful, predominantly green shade.
The soil should be organically rich, well-draining, and capable of retaining consistent moisture. Since these plants are heavy feeders, amending the planting area with compost or aged manure is beneficial. The preferred soil acidity is slightly acidic to neutral, with a pH range between 6.0 and 7.0.
Rhizomes should only be planted outdoors after the last expected frost, when the soil temperature has consistently warmed to at least 60 to 65 degrees Fahrenheit. Plant the fleshy rhizomes horizontally, positioning the “eyes,” or growth points, facing upward, about one to four inches deep beneath the soil surface. For tall varieties, space the rhizomes approximately 18 to 24 inches apart to allow for their substantial spread and mature size. Gardeners in cooler climates can gain a head start by potting the rhizomes indoors in moist soil about a month before the last frost date, which promotes earlier summer blooms.
Routine Care and Feeding
Tropicanna Canna Lilies require consistent maintenance and are heavy drinkers and feeders during the active growing season. The large foliage transpires a significant amount of water, so the soil must be kept consistently moist and never allowed to fully dry out. In periods of extreme heat or when growing in containers, daily deep watering may be necessary.
The plant’s vigorous growth rate necessitates a regular fertilization schedule to support both the abundant foliage and the continuous flowering. Apply a balanced, slow-release granular fertilizer, such as a 10-10-10 formulation, at the beginning of the growing season in early spring. Supplement this initial feeding with a liquid fertilizer application every four to six weeks during the summer months.
Choosing a fertilizer slightly higher in phosphorus can encourage more prolific flowering, but avoid excessive nitrogen, which tends to promote lush green foliage at the expense of bloom production. Routine grooming is necessary to maintain the plant’s tidy appearance and maximize its flowering display. Deadheading spent flower stalks down to the next lower side shoot or leaf node encourages the plant to produce subsequent blooms. Promptly remove any yellowed, damaged, or tattered leaves throughout the season to redirect the plant’s energy toward healthy, new growth.
Protecting and Preparing for Winter
For gardeners in USDA Hardiness Zones 7 and below, where the ground freezes, the Tropicanna Canna Lily must be lifted and stored indoors to survive the winter dormancy period. The best time to begin the process is after the first light frost has caused the foliage to turn yellow or brown, signaling the plant has entered dormancy. Cut the entire stalk back, leaving a stub of about six inches above the soil line, which serves as a handle for lifting the rhizome clump.
Carefully dig up the rhizomes, taking care not to damage the fleshy root structures, and gently shake off the loose soil without washing them, as excess moisture can encourage rot during storage. The rhizomes should then be cured by placing them in a warm, dry, protected location for a few days to allow the outer skin to slightly toughen. Once cured, store the rhizomes in a cool, dark, dry, and well-ventilated space, such as a basement or cellar, where temperatures remain consistently between 40 and 50 degrees Fahrenheit.
Store the rhizomes nestled in a material like peat moss, vermiculite, or sawdust, ensuring the individual pieces do not touch, which minimizes the risk of moisture transfer and fungal growth. Check the stored rhizomes monthly to confirm they are not shriveling from drying out or developing mold from too much humidity.
Pest Management
The plant’s broad leaves can be susceptible to pests during the growing season, particularly the Canna leaf roller, a caterpillar whose larvae roll themselves into the leaves. Treat active infestations with an organic insecticide containing Bacillus thuringiensis (Bt). Destroy any rolled leaves found during the winterizing process, as they can harbor overwintering pests.