If you’re planning your garden layout, knowing how tall do canna lilies grow is essential for placing them correctly. These tropical-looking plants can create a stunning backdrop or a bold focal point, but their size can vary quite a bit.
In this guide, we’ll cover the maximum height and spread you can expect, along with the factors that influence their growth. You’ll learn how to choose the right variety and care for them to reach their full, impressive potential.
How Tall Do Canna Lilies Grow
On average, most common canna lily cultivars reach a height between 3 to 6 feet. However, their maximum height can range from a compact 18 inches for dwarf varieties to a towering 10 feet for the largest species.
The spread, or width, of a canna clump is typically 1.5 to 2 feet wide, but it can expand further over time as the rhizomes multiply. Always check the specific variety’s tag for its expected dimensions.
Factors That Influence Canna Lily Height
Several key elements determine whether your canna lily hits the lower or upper end of its height range. It’s not just about genetics.
1. Variety and Genetics
This is the most significant factor. Breeders have developed cannas for different garden roles. Dwarf types like ‘Tropical Rose’ stay small, while giants like ‘Australia’ or species like Canna musifolia are naturally tall.
2. Sunlight Availability
Cannas need full sun for strongest growth. Plants in partial shade will often stretch and become leggy as they reach for light, but they might not achieve the same robust height or flower as well as those in full sun.
3. Soil Quality and Fertilization
Rich, moist, well-draining soil fuels growth. A regular feeding schedule with a balanced fertilizer, especially one higher in phosphorus for blooms, supports them in reaching their maximum size. Poor, dry soil stunts them.
4. Climate and Growing Season Length
In warm climates with long growing seasons, cannas have more time to grow tall. In cooler zones, where they are started later or must be lifted for winter, they may be slightly shorter.
5. Watering Practices
These are thirsty plants. Consistent moisture is crucial, especially during peak summer heat. Irregular watering can stress the plant and limit its vertical growth.
Popular Varieties and Their Typical Sizes
Here’s a quick reference list to help you choose:
- ‘Tropicanna’® (Gold): Famous for striped leaves. Height: 4-6 ft. Spread: 1.5-2 ft.
- ‘Australia’: Dramatic dark foliage with red flowers. Height: 4-5 ft. Spread: 1.5 ft.
- ‘Pretoria’ (Bengal Tiger): Striking variegated leaves. Height: 5-6 ft. Spread: 2 ft.
- ‘Phasion’: Another vibrant variegated type. Height: 4-5 ft. Spread: 1.5 ft.
- ‘Cleopatra’: A mix of flower colors on one plant. Height: 3-4 ft. Spread: 1.5 ft.
- ‘Tropical Rose’ (Dwarf): Deep pink flowers on a small plant. Height: 18-24 inches. Spread: 1 ft.
- Canna musifolia (Giant Bird of Paradise Canna): Massive green leaves. Height: 8-10+ ft. Spread: 3-4 ft.
Managing the Spread of Canna Lilies
While height gets attention, the spread is important for spacing. Cannas grow from rhizomes that multiply underground each year.
To control spread and maintain plant health, division every 2 to 4 years in spring is recommended. Here’s how:
- In spring, carefully dig up the entire clump of rhizomes.
- Wash off excess soil so you can see the growth points (eyes) and roots.
- Using a sharp, clean knife, cut the rhizome into sections. Each section needs at least 2-3 eyes.
- Replant one section, and give the others away or expand your planting.
Planting for Maximum Impact
Use their height and spread to your advantage in garden design. Tall varieties work well as a summer hedge or screen. They’re perfect for the back of a border.
Medium-sized cannas make excellent thriller elements in large containers. Dwarf types are superb for the front of beds or in patio pots. Always group at least three of the same variety together for a bold statement.
Common Problems That Can Stunt Growth
If your cannas aren’t reaching there expected size, check for these issues:
- Overcrowding: Dense clumps compete for resources. Divide them.
- Pests: Canna leaf rollers and caterpillars can damage foliage, weakening the plant. Treat with appropriate organic or conventional controls.
- Water Stress: Wilting or crispy leaf edges are a sign. Increase watering frequency.
- Nutrient Deficiency: Yellowing leaves or poor flowering can indicate hunger. Apply a balanced fertilizer.
Step-by-Step Care for Tall, Healthy Cannas
Follow this simple care routine to ensure your plants thrive.
Planting Time
Plant rhizomes in spring after the last frost, when soil is warm. Place them 4-6 inches deep and 1.5 to 2 feet apart, depending on the variety’s spread.
Seasonal Feeding Schedule
- At planting: Mix compost into the soil.
- Monthly during growth: Use a 5-10-5 or similar bloom-boosting fertilizer.
- Stop feeding in early fall to allow the plant to harden off before dormancy.
Winter Care in Cold Climates
After the first frost blackens the foliage, cut stems back to 6 inches. Carefully dig up the rhizome clump, let it dry for a day, and store in barely-damp peat moss or newspaper in a cool, dark place like a garage. Replant in spring.
FAQ About Canna Lily Size
How fast do canna lilies grow?
They grow remarkably fast once the weather warms. A rhizome can produce a 4-foot plant in a single season, which is part of there appeal.
Can I control the height of my canna lilies?
You can’t shorten a tall variety, but you can choose dwarf types. Pinching is not effective and will reduce flowering. The best control is selecting the right cultivar from the start.
Do canna lilies spread aggressively?
They spread steadily but are not typically invasive like running bamboo. The clump increases in diameter each year, but is easily managed by division.
What is the tallest canna lily ever recorded?
While anecdotal, some gardeners report species like Canna musifolia exceeding 12 feet in ideal, tropical conditions. Most garden cultivars top out around 6-8 feet.
How much space should I leave between plants?
For most varieties, 18 to 24 inches between rhizomes is ideal. This gives them room to spread without immediate competition and ensures good air circulation to prevent disease.
Understanding how tall do canna lilies grow helps you harness their dramatic effect. By matching the variety to your space and providing simple, consistent care, you can enjoy these architectural beauties at there full potential. Remember to consider both there vertical height and horizontal spread when placing them in your garden for a balanced and stunning display all season long.