Canna (Canna (group))
Dramatic flowering Canna (group) prized for large leaves and vibrant red, orange, pink, and yellow blooms. Zones 7-10.
Complete Plant Information
Overview
The Canna provides immediate, bold tropical impact in temperate gardens, making the Canna (group) a favorite for summer drama. These rhizomatous perennials are celebrated not only for their spikes of vibrant flowers but also for their stature and large, paddle-shaped foliage, which significantly contributes texture and color even when not in bloom. Cultivars of Canna offer numerous color combinations, attracting wildlife like hummingbirds to the garden landscape.
Though tropical in appearance, successful cultivation of the Canna (group) is achievable in USDA Zones 7 through 10, with rhizomes requiring specific overwintering procedures in cooler regions. They thrive best when receiving full sun and require consistent moisture to support their impressive growth habit. This plant is grown as an annual in many northern regions but provides superb, low-effort color throughout the peak growing season.
Fast Facts
- Plant Family: Cannaceae
- Plant Type: Bulb
- Hardiness Zones: USDA Zones 7-10
- Size at Maturity:
- Height: 1.5-8 ft
- Spread: 1.5-6 ft
- Bloom Time: July to September
- Bloom Description: Red, orange, pink, yellow, cream, bicolors
- Sun Exposure: Full sun
- Water Needs: Medium
- Maintenance Level: Medium
How to Grow
Planting your Canna rhizomes should occur in the spring only after all danger of frost has passed, ensuring the soil has had a chance to warm. For optimal performance, locate your Canna in a spot receiving full sun. The soil must be organically rich, well-drained, and kept consistently moist throughout the growing season. Plant the rhizomes 4 to 6 inches deep and space them 18 to 24 inches apart to allow for mature spread.
During the active growing season, maintain a medium watering schedule, ensuring the soil does not dry out completely, which is crucial for these moisture-loving plants. Deadheading is simple: immediately remove entire flowering stems after the blooms fade to encourage continuous production of flowers until late summer or early fall.
For gardeners in Zones 7-10, the rhizomes are reliably hardy when planted directly in the ground. However, when frost hits, cut the plants back to ground level. If you live outside this range or wish to ensure survival, you must lift the rhizome clumps in the fall. Store them dry, submerged in peat moss or vermiculite, in a cool location (above 40°F). Lightly misting the storage medium during winter is sometimes necessary to prevent rhizomes from desiccating.
Landscape Uses
The stature and vibrant coloration of the Canna (group) make it indispensable for creating dramatic focal points in landscape designs. These showy plants look magnificent when massed or grouped within garden beds and borders, providing height that contrasts beautifully with lower-growing annuals and perennials. Their bold, tropical leaves are particularly stunning when backlit by the afternoon sun, maximizing their visual impact.
Beyond borders, Canna plants perform exceptionally well in large containers, where their height acts as a vertical accent for patio designs. They are also suitable for near foundation plantings, provided there is adequate space for their mature size and sufficient cultural care regarding moisture and drainage.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Canna is a genus derived from rhizomatous, tropical and subtropical, herbaceous perennials producing flower spikes from summer into early fall atop erect stems sheathed in substantial, paddle-shaped leaves. Cultivars are broadly available featuring colorful foliage alongside flowers spanning warm hues like red, yellow, pink, and creamy white. The genus name originates from the Greek word kanna, meaning “reed.”
Tolerances
Potential Problems
A primary concern for Canna cultivation is avoiding overly saturated conditions, as rhizomes are highly susceptible to rot if planted in wet, poorly drained soils. Gardeners should also monitor for common fungal and bacterial issues, including leaf spots, rust, and bacterial blight, ensuring proper air circulation helps mitigate these risks. Furthermore, routine inspection is necessary as foliage is attractive to chewing pests such as Japanese beetles, various caterpillars, slugs, and snails.
Frequently Asked Questions
What hardiness zones is Canna suitable for?
Canna rhizomes are reliably hardy in USDA Zones 7 through 10, though lifting and overwintering is required for colder areas.
How large does Canna grow?
Mature Canna plants can reach heights between 1.5 and 8 feet, with a spread ranging from 1.5 to 6 feet, depending on the specific cultivar grown.
What sun exposure does Canna need?
Canna requires full sun exposure to achieve its best growth and most prolific blooming performance.
When does Canna bloom?
The impressive bloom time for this group is generally from July through September, offering a spectrum of red, orange, pink, yellow, cream, and bicolor flowers.
Conclusion
The diverse Canna (group) remains a powerhouse plant for gardeners seeking instant structure, bold foliage, and electrifying summer color. Whether used as a tropical screen or a container centerpiece, the visual return from this Canna is substantial. Before planting, verify your local hardiness zone and ensure you have planned for adequate space and consistent watering to enjoy this magnificent display.
Companion Planting
Selecting suitable companion plants ensures your Canna display thrives aesthetically and culturally. Since Canna requires full sun and medium, consistent moisture, pair it with plants that share these needs, such as upright ornamental grasses, large-leafed hostas placed where they receive morning sun, or tropical annuals like Caladiums or Elephant Ears (Colocasia). The broad leaf texture of Canna contrasts beautifully with fine-textured foliage, enhancing the overall garden composition throughout the summer season.
Propagation Tips
The most common and reliable method for increasing your Canna stock involves division of the rhizomes. This process should be done in the spring just before the rhizomes are replanted outdoors or potted up for forcing. Carefully excavate the rhizome clumps, often revealing several “eyes” or growth nodes. Use a clean, sharp spade or trowel to divide the mass into sections, ensuring each healthy division has at least one viable eye attached. Replanting these divisions immediately achieves exactly what the culture requires: propagation before outdoor replanting.
