Cannas: How to Plant, Grow, and Care for These Tropical Showstoppers

Cannas rank among the most flamboyant summer bulbs, their tropical American heritage on full display in ruffled spikes that taper to refined buds.

These perennials offer an astonishing range of colors, immense paddle-shaped leaves often marked with striking veins, and sheathing leafstalks in shades of green or bronze.

Even without flowers, cannas would command attention with their great reedy canes and palmy foliage. But they do bloom—prolifically—from late spring or early summer right up to frost.

Turn-of-the-century gardeners adored cannas and grew them from seed, but germination is tricky; modern gardeners are better off purchasing tubers from specialists.

Planting Cannas

• These exotic, tropical plants crave sunshine and fertile, moist soil, yet they're surprisingly low-maintenance.
• In short-season areas, start rhizomes indoors in small pots.
• Where not hardy, plant outdoors in early summer—around the same time you set out tomato plants.
• Loosen soil to 12–15 inches deep and incorporate a 2- to 4-inch layer of compost.
• Dig holes 2–3 inches deep, set rhizomes with eyes facing up, cover firmly, and water thoroughly.
• Space rhizomes 1 to 4 feet apart depending on variety.
• If growing from seed, note the low germination rate; seeds require filing or an acid bath to break their hard coats.

Care Through the Season

• Water generously during dry spells—cannas need consistent moisture. If rainfall is under 1 inch per week, supplement with irrigation.
• Maintain a thin mulch layer to conserve soil moisture.
• Stake tall varieties to prevent wind damage.
• Deadhead spent flowers to encourage continued blooming.
• Cut each stem to the ground after flowering.
• After autumn frost blackens foliage, cut back stems, lift rhizomes, and store in barely-moist peat or leaf mold in frost-free conditions. Keep rhizomes separated.
• In the Deep South, leave cannas in ground until clumps become matted (every 3–4 years), then divide in winter and replant in enriched soil.
• Some zone 7 gardeners report success overwintering in ground with heavy mulch protection.

Pests and Diseases

• Slugs, snails, spider mites, and caterpillars may appear.
• Rust, fungal leaf spot, and bacterial blight are common.
• Bean yellow mosaic and tomato spotted wilt viruses can occur.

Harvest and Storage

• Store lifted rhizomes in a dry place at 45–50°F. Prevent desiccation by sprinkling surrounding sand or soil if needed.
• In spring, divide tubers with a sharp knife, ensuring each piece has one eye on substantial rootstock.

Recommended Varieties

• Dwarf cannas (under 3 feet) suit modern gardens. 'Picasso' (2½ feet) bears yellow flowers freckled with spots.
• Standard varieties (4–6 feet) need 20–24 inches per rhizome. 'The President' (red), 'Yellow King Humbert' (spotless yellow), 'Rosamond Cole' (orange-edged gold), 'City of Portland' (salmon pink).
• Tall, drought-tolerant types (over 6 feet). 'Los Angeles' offers rich deep pink with large, open-faced florets.
• 'Bengal Tiger' — stunning even out of bloom, with green-and-yellow-striped, maroon-edged leaves and bright orange flowers.

Wit & Wisdom

Flowers are words which even a babe may understand.
—Arthur Cleveland Coxe, American poet (1818–1896)