Growing Cannas: A Complete Guide to Planting, Care, and Overwintering

Few summer bulbs bring such flamboyant, tropical drama to the garden as cannas. With their towering reedy canes, immense paddle-shaped leaves in shades of green or bronze, and ruffled flower spikes that bloom from early summer until frost, these perennials are showstoppers whether in borders, containers, or waterside plantings.

Why Grow Cannas?

Native to tropical America, cannas offer bold foliage and vibrant blossoms in a spectrum of reds, oranges, yellows, pinks, and salmons. Their architectural presence alone—reaching 3 to 10 feet depending on variety—makes them worth growing even before the flowers appear. They thrive in heat, tolerate moist soils, and ask for little beyond sun and consistent moisture.

Planting Cannas

When and Where to Plant

• Timing: Plant outdoors after all danger of frost has passed, roughly when you’d set out tomato plants. In short-season climates, start rhizomes indoors in pots 4–6 weeks earlier.
• Sun: Full sun (6+ hours) yields the best growth and flowering.
• Soil: Fertile, moisture-retentive, well-drained soil. Amend the planting area by loosening soil 12–15 inches deep and mixing in a 2–4 inch layer of compost.

How to Plant Rhizomes

1. Dig a hole 2–3 inches deep.
2. Place the rhizome horizontally with the growing eyes facing up.
3. Cover with soil, firm gently, and water thoroughly.
4. Space rhizomes 1–4 feet apart depending on the mature size of the variety.

Note: Growing from seed is possible but germination is low and seeds require scarification (filing or acid bath). Most gardeners purchase rhizomes for reliable results.

Ongoing Care

Watering and Mulching

Cannas are thirsty plants. Provide at least 1 inch of water per week, more during dry spells. A thin layer of organic mulch helps retain soil moisture and suppress weeds.

Feeding

Apply a balanced fertilizer monthly during the growing season to support vigorous growth and continuous bloom.

Deadheading and Staking

• Remove spent flower spikes to encourage reblooming.
• Stake tall varieties in windy sites to prevent toppling.

Fall Cleanup and Winter Storage (Zones 3–8)

1. After frost blackens the foliage, cut stems to the ground.
2. Lift rhizomes carefully with a fork.
3. Shake off excess soil; do not wash.
4. Store in barely-moist peat moss, vermiculite, or leaf mold at 45–50°F in a frost-free location. Keep rhizomes from touching to prevent rot.

Southern Gardens (Zones 9–10)

In frost-free areas, cannas can remain in the ground year-round. Every 3–4 years, dig and divide crowded clumps in winter, replanting in enriched soil. Some zone 7 gardeners successfully overwinter cannas in situ with a heavy mulch blanket.

Pests and Diseases

• Insects: Slugs, snails, spider mites, caterpillars.
• Diseases: Rust, fungal leaf spot, bacterial blight, and viruses such as bean yellow mosaic and tomato spotted wilt.

Good air circulation, clean cultivation, and prompt removal of affected foliage minimize problems.

Dividing and Propagating

In spring, cut stored rhizomes with a sharp knife so each division has at least one strong eye and a substantial piece of rootstock. Plant divisions as you would whole rhizomes.

Recommended Varieties

Dwarf (Under 3 ft) – Ideal for Containers

• ‘Picasso’ – 2½ ft, yellow flowers speckled with red freckles.

Standard (4–6 ft) – Classic Border Plants

• ‘The President’ – Deep red.
• ‘Yellow King Humbert’ – Clear yellow.
• ‘Rosamond Cole’ – Orange edged with gold.
• ‘City of Portland’ – Soft salmon pink.

Tall & Dramatic (Over 6 ft)

• ‘Los Angeles’ – Rich deep pink, large open-faced florets.
• ‘Bengal Tiger’ – Striking green-and-yellow striped leaves with maroon edges, bright orange flowers; ornamental even out of bloom.

Wit & Wisdom

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