The Canna ‘Tropicana’ (Canna indica ‘Phasion’) is an ornamental plant known for its striking, tropical appearance. This cultivar features flamboyant, variegated foliage with stripes of red, pink, yellow, gold, and green, which serve as a colorful backdrop for its bright tangerine flowers. Reaching six feet in height, this perennial, grown from a rhizome, creates a dramatic visual impact, making it popular for landscapes or container displays.
Creating the Ideal Growing Environment
The Canna ‘Tropicana’ requires full sun and warmth to achieve its most vibrant coloration. Position the plant where it can receive a minimum of six hours of direct sunlight daily. Optimal growth occurs when daytime temperatures consistently exceed 75°F.
Planting ‘Tropicana’ in rich, highly organic soil supports vigorous growth. The soil should be fertile and consistently moist, yet offer adequate drainage to prevent waterlogging around the rhizomes. A slightly acidic to neutral pH, ideally ranging from 6.0 to 6.5, allows for efficient nutrient absorption. If the soil is heavy or poorly draining, amending it with compost or peat moss creates a loose, nutrient-dense foundation for healthy root development.
Watering and Fertilizing Requirements
Canna ‘Tropicana’ demands consistent moisture throughout the active growing season. The soil should never be allowed to dry out completely, especially during hot weather. Deep watering at least once per week is necessary, and this frequency may need to increase during periods of intense heat or when the plant is grown in containers.
The Canna benefits from regular nutrient supplementation due to its fast growth. Begin feeding in early spring once new growth is visible, and continue until late summer. Apply a balanced, slow-release granular fertilizer, such as a 10-10-10 or 5-10-5 formulation, every three to four weeks. To promote prolific flowering, a liquid feed higher in phosphorus can be applied every four weeks.
Preparing the Plant for Dormancy
For gardeners in cooler climates where the ground freezes, lifting the rhizomes is required for successful overwintering. The process begins after the first hard frost, which signals dormancy by blackening the foliage. Cut the stems back to approximately four to six inches above the soil line, leaving a short handle for lifting.
Carefully dig up the entire clump of rhizomes using a garden fork, avoiding bruising the underground structures. Remove excess soil by hand, but avoid washing the rhizomes, as moisture promotes rot during storage. Allow the rhizomes to cure for a few days in a protected, frost-free location to dry the cuts and remaining soil slightly.
Proper storage involves placing the semi-dried rhizomes in a container with ventilation holes, such as a cardboard box or plastic bin. Cover them with a dry medium like peat moss, wood shavings, or vermiculite. Keep the rhizomes cool, dark, and dry, ideally below 50°F, to prevent premature sprouting. Check the stored rhizomes monthly to remove any pieces showing mold or rot, or mist lightly if they appear shriveled.
Addressing Common Pests and Problems
The Canna ‘Tropicana’ can attract a few common garden pests due to its large, soft leaves.
Chewing Pests
Chewing insects, most notably caterpillars, including the canna leaf roller, create holes or roll themselves up inside the leaves to feed. Hand-picking caterpillars is an effective control method for minor infestations.
Sucking Pests
Sucking pests like aphids and spider mites can be problematic, especially on new growth or in hot, dry conditions. Aphids cluster on stems and leaf undersides, leaving behind a sticky residue called honeydew. Spider mites are indicated by fine webbing and a silvery or scorched appearance on the foliage. Regularly inspecting the undersides of the leaves allows for early detection. Treatments can range from a strong jet of water to dislodge the pests to an application of insecticidal soap.
Environmental Issues
Leaf browning or scorching is a common visual issue, often a result of insufficient watering during peak summer heat or too much wind exposure. Wilting can indicate both under-watering and, more seriously, root rot caused by overwatering or poor drainage. Monitoring soil moisture is the best way to diagnose the cause of wilting and prevent the plant from succumbing to fungal issues.