If you want a tropical splash of color in your garden, learning how to care for canna lily is your first step. These bold plants with their large leaves and vibrant flowers are surprisingly easy to grow with the right knowledge.
They thrive in heat and sunlight. With a few simple care tips, you can enjoy their dramatic display from summer right into fall.
How to Care for Canna Lily
Successful canna care revolves around a few key needs: plenty of sun, consistent water, and good nutrition. Think of them as the sun-loving, hungry teenagers of the plant world. They grow fast and need support to look their best.
Sunlight and Temperature Needs
Cannas are sun worshippers. They need a minimum of six hours of direct sunlight each day to flower well and maintain strong foliage. More sun is generally better.
They are tender perennials, thriving in warm conditions. Here’s what to know about temperature:
- Ideal growing temperatures are between 70°F and 85°F.
- They will not survive freezing temperatures. In zones below USDA 8, rhizomes must be lifted in fall.
- Growth begins when soil temperatures reach about 60°F. Planting too early in cold, wet soil can cause the rhizomes to rot.
Soil and Planting Requirements
These plants are not overly picky about soil but they do demand good drainage. A rich, moisture-retentive yet well-draining soil is perfect. You can improve your garden soil by mixing in plenty of compost.
When planting canna rhizomes, follow these steps:
- Wait until all danger of frost has passed and the soil has warmed.
- Dig a hole 4 to 6 inches deep.
- Place the rhizome horizontally with the eyes (growth points) facing upwards.
- Cover with soil and water thoroughly.
- Space rhizomes about 1 to 2 feet apart, as plants can get quite wide.
For container planting, use a large pot with drainage holes and a quality potting mix. This is a great option for patios or cooler climates where you need to move them indoors.
Watering and Humidity
Cannas love water. They naturally grow near pond edges and in damp soils. Consistent moisture is crucial, especially during their peak growing and flowering period.
- Water deeply at least once a week, more often during hot, dry spells.
- Container-grown cannas will need watering almost daily in summer heat.
- Avoid letting the soil dry out completely, as this stresses the plant and reduces flowering.
They also appreciate humidity, which is why they often perform exceptionally well in humid summer climates. If your air is dry, the extra watering helps compensate.
Fertilizing for Best Blooms
To support their rapid growth and big flowers, cannas are heavy feeders. A balanced, slow-release fertilizer applied at planting time is a good start. Then, during the growing season, you should feed them regularly.
Many gardeners use a liquid fertilizer every 4-6 weeks. Look for a formula that is balanced (like 10-10-10) or one slightly higher in phosphorus to promote blooming. Just be careful not to over-fertilize with nitrogen, as this can encourage leafy growth at the expense of flowers.
An annual top-dressing with compost in the spring also provides excellent, gentle nutrition.
Pruning and Deadheading
Regular pruning keeps your cannas looking tidy and encourages more blooms. The main tasks are deadheading and removing old leaves.
- Deadhead spent flowers by cutting the flower stalk down to the next lateral bud or to the base. This tells the plant to produce more flower shoots instead of putting energy into seed pods.
- Remove any yellowing or damaged leaves at the base to improve air circulation and appearance.
- At the end of the season, after frost blackens the foliage, you can cut the entire plant back to about 4-6 inches.
Overwintering Rhizomes
In climates with freezing winters, you must dig up the rhizomes for storage. Do this after the first frost has killed the foliage.
- Carefully dig up the clump, trying not to damage the rhizomes.
- Shake off excess soil and cut the stems back to about 2 inches.
- Let the rhizomes cure (dry) for a few days in a warm, airy spot.
- Store them in a cool, dry place for the winter. You can pack them in peat moss, sawdust, or newspaper in a cardboard box or mesh bag. The ideal storage temperature is between 45°F and 60°F.
Check on them once or twice during winter to ensure they are not drying out completely or rotting. A slightly shriveled rhizome is okay; a mushy one should be discarded.
Common Pests and Problems
Cannas are relatively trouble-free but can face a few issues. The most common pest is the canna leaf roller caterpillar, which chews leaves and rolls them up. Handpick them or use an appropriate organic insecticide like Bt (Bacillus thuringiensis).
Other potential problems include:
- Japanese Beetles: They skeletonize leaves. Hand-picking in the morning is effective for small infestations.
- Slugs and Snails: They chew holes in leaves, especially in damp conditions. Use bait or traps.
- Fungal Leaf Spot: Appears as spots on leaves. Improve air circulation, avoid overhead watering, and remove affected leaves.
- Bud Drop: Sometimes flower buds fail to open and fall off. This is often caused by stress from irregular watering or extreme temperature fluctuations.
Propagating Your Cannas
The easiest way to propagate cannas is by dividing the rhizomes. This is best done in spring just before planting, or when you dig them up in fall. Each division needs at least one healthy eye (growth node) to become a new plant.
Use a sharp, clean knife to cut the rhizome. Let the cut surfaces dry for a day before planting or storing to prevent rot. This division also helps control the size of your clumps and rejuvenates older plants that may have become crowded.
FAQ: Canna Lily Care Questions
Why is my canna lily not flowering?
The most common reasons are not enough sun, overcrowded rhizomes that need dividing, or a lack of fertilizer. Ensure they get full sun and feed them regularly during the growing season.
Can cannas grow in partial shade?
They can survive in partial shade, but flowering will be significantly reduced and the growth may be leggy. For the best performance, full sun is always recommended.
How often should I water my canna plants?
Water deeply when the top inch of soil feels dry. This could mean once or twice a week in the ground, or even daily for potted plants in hot weather. They like consistently moist soil.
Do canna lilies come back every year?
In warm climates (USDA zones 8-11), they will return perennially. In cooler zones, you must treat them as annuals or dig and store the rhizomes indoors over winter.
What’s the best fertilizer for canna lilies?
A balanced, slow-release granular fertilizer at planting, followed by a liquid feed high in phosphorus (the middle number on the fertilizer bag) every month during summer will support strong blooms.
Should I deadhead my canna flowers?
Yes, definitely. Removing spent flowers encourages the plant to produce new bloom stalks, extending your flowering season right up until frost.
With these essential care tips, your canna lilies will become a reliable and stunning highlight in your garden. Their low-maintenance nature once you understand their needs makes them a fantastic choice for both beginners and experienced gardeners looking for a big impact. Just remember: sun, water, food, and a cozy winter inside if you get frost. Then sit back and enjoy the tropical show all season long.