Table of Contents
- Introduction
- Getting to Know Cannas
- Finding the Perfect Spot: Right Plant, Right Place
- When to Plant Your Canna Rhizomes
- How to Plant Cannas: A Step-by-Step Guide
- Growing Cannas in Containers
- Essential Summer Care for Lush Growth
- Handling Common Pests and Challenges
- Overwintering Cannas: Protecting Your Investment
- Designing with Cannas
- Why We Love Cannas
- FAQ
Introduction
There is nothing quite like the sight of a canna lily in full midsummer glory. With their towering, banana-like leaves and vibrant, jewel-toned flowers, these plants bring an immediate tropical energy to any backyard.
At Longfield Gardens, we believe that every gardener should experience the joy of watching a canna rhizome transform into a six-foot-tall masterpiece in a single season.
This guide will walk you through everything you need to know about selecting, planting, and caring for these magnificent plants to ensure your garden feels like a private island getaway. If you want a deeper background on the plant itself, our All About Cannas guide is a helpful companion. (longfield-gardens.com)
Getting to Know Cannas
Before we dig into the soil, it is helpful to understand exactly what a canna is. Although many people refer to them as "canna lilies," they are not true lilies at all. They are more closely related to gingers and bananas. This relationship is evident in their growth habit: they emerge from thick, starchy underground stems called rhizomes.
These rhizomes act as energy storage units, allowing the plant to push out massive amounts of growth in a very short period. In the right conditions, a single canna can grow several feet in a few months. Their foliage is just as important as their flowers, with leaves that can be solid green, deep bronze, or even variegated with stripes of yellow, orange, and white.
The flowers themselves appear on tall stalks and come in a wide range of warm colors, including red, orange, yellow, pink, and cream. Some varieties even feature bi-color petals with intricate spotting. Because they are tropical in nature, cannas love the sun and are very comfortable in humid conditions. They are hardy perennials in USDA zones 7 through 10, while gardeners in zones 6 and colder typically grow them as annuals or lift the rhizomes to store indoors for the winter. For a quick way to check your growing zone, the Hardiness Zone Map can help. (longfield-gardens.com)
Finding the Perfect Spot: Right Plant, Right Place
Success with cannas starts with choosing the right location. Because they are such vigorous growers, they have specific needs when it comes to light, soil, and space. Getting these basics right is the easiest way to ensure a beautiful display.
Sun Exposure
Cannas are true sun-worshippers. To reach their full height and produce the maximum number of flowers, they need at least six to eight hours of direct sunlight every day. While they can grow in partial shade (around four hours of sun), the plants often become "leggy," meaning the stems grow thin and weak as they reach for the light.
Soil and Drainage
Unlike many other flower bulbs that require perfectly sharp drainage to prevent rot, cannas are quite happy in soil that stays consistently moist. In fact, some varieties can even be grown in the shallow edges of a water feature or pond. However, for standard garden beds, we recommend a rich, loamy soil that is high in organic matter.
Protection from Wind
Because cannas have large, soft leaves, they can sometimes act like sails in a high-wind area. Strong gusts can shred the foliage, leaving the plants looking a bit tattered. If you live in a particularly windy region, try to plant your cannas near a fence, a wall, or a line of sturdy shrubs that can act as a windbreak.
Key Takeaway: For the most vibrant colors and tallest stems, plant your cannas in a sunny, sheltered spot with rich soil that stays moist but not soggy.
When to Plant Your Canna Rhizomes
Timing is one of the most important factors in a successful canna growing guide. Because cannas are tropical plants, they are very sensitive to cold soil and frost. If you plant them too early, the rhizomes may sit dormant in cold, wet earth, which can lead to rot before the plant even gets started.
The Soil Temperature Rule
The most reliable way to know when to plant is to check your soil temperature. We recommend waiting until the soil has warmed to at least 60°F. For most gardeners, this coincides with the time you would typically plant tomatoes or peppers outdoors.
Starting Early Indoors
If you live in a northern climate with a short growing season, you can get a head start by "starting" your cannas indoors about four to six weeks before the last frost. Simply plant the rhizomes in pots with a high-quality potting mix and keep them in a warm, sunny window or under grow lights.
Regional Variations
- Southern Zones (7-10): You can often plant as early as March or April, depending on your local weather patterns. In these zones, cannas can stay in the ground year-round.
- Northern Zones (3-6): Planting usually happens in late May or early June. In these areas, the rhizomes must be lifted in the fall if you want to save them for next year.
For more seasonal timing guidance, the shipping information page is also useful because it ties plant availability to planting windows. (longfield-gardens.com)
How to Plant Cannas: A Step-by-Step Guide
Once the weather is warm and your site is prepared, planting is a simple process. Cannas are very forgiving, but following these steps will give them the best possible start.
1. Prepare the Soil
Loosen the soil to a depth of about 10 to 12 inches. This allows the roots to spread easily. At this stage, you can mix in a balanced, slow-release fertilizer or a generous amount of compost to provide a steady supply of nutrients.
2. Positioning the Rhizomes
Dig a hole about 4 inches deep. Place the canna rhizome in the hole horizontally. If you look closely at the rhizome, you will see small bumps or points—these are the "eyes" or growth points. Ideally, these should point upward, but don't worry if you can't tell which way is up.
3. Spacing
Cannas need room to breathe and expand. For standard varieties that grow 4 to 6 feet tall, space the rhizomes about 18 to 24 inches apart. For dwarf varieties, you can space them closer together, around 12 inches apart. Giving them enough space helps prevent the spread of fungal issues by ensuring good air circulation between the large leaves.
4. Covering and Watering
Cover the rhizomes with 2 to 3 inches of soil and firm it down gently with your hands to remove any large air pockets. Water the area thoroughly right after planting to settle the soil.
What to Do Next: Planting Checklist
- Check that the danger of frost has passed.
- Amend your planting site with compost.
- Plant rhizomes 4 inches deep and 18-24 inches apart.
- Water well to settle the soil.
- Mark the spot with a garden stake so you don't accidentally dig them up before they sprout.
Growing Cannas in Containers
If you don't have a large garden bed, or if you want to add some height to your patio, cannas are excellent candidates for container gardening. Because they grow so large, they provide an instant "thriller" element for your pot arrangements.
Choosing the Right Pot
Cannas have extensive root systems and grow quite heavy, so you need a large, sturdy container. We recommend a pot that is at least 12 to 18 inches in diameter for a single rhizome. Heavier materials like ceramic, terra cotta, or thick resin are better than lightweight plastic, as they are less likely to tip over when the canna reaches its full height.
Potting Mix and Planting
Use a high-quality, well-draining potting mix. Avoid using garden soil in pots, as it can become too compacted and limit root growth. Plant the rhizome about 4 inches deep, just as you would in the ground. Because containers dry out faster than garden beds, you may need to water your potted cannas more frequently—sometimes every day during the peak of summer.
Container Design Ideas
Cannas look stunning when planted alone, but they also pair beautifully with "filler" and "spiller" plants. Consider planting low-growing annuals like sweet alyssum, petunias, or trailing vinca around the base of the canna. These will cover the soil and add extra color while the canna provides the vertical drama.
If you like container combinations, the Summer Blooming Bulbs for Containers page is a useful place to browse more ideas. (longfield-gardens.com)
Essential Summer Care for Lush Growth
Cannas are vigorous plants, and like any high-performer, they need a bit of support during the growing season. If you provide them with enough "fuel" in the form of water and fertilizer, they will reward you with non-stop growth and flowers.
Watering: The Key to Happy Cannas
Water is the single most important factor in canna care. While many bulbs prefer to dry out between waterings, cannas like to stay consistently moist. During the heat of July and August, your cannas may need a deep soaking two or three times a week. If the leaves begin to roll or the edges turn brown and crispy, it is a sign that the plant is thirsty.
One effective way to maintain moisture is to apply a 2-inch layer of mulch (such as shredded bark or straw) around the base of the plants. This helps keep the soil cool and reduces water evaporation.
Fertilizing for Big Blooms
Cannas are "heavy feeders." To support those massive leaves and constant flower production, they need regular nutrition. We suggest applying a balanced, water-soluble fertilizer every two to three weeks during the growing season. Alternatively, you can use a slow-release granular fertilizer at planting time and again in mid-July. Look for a fertilizer that is slightly higher in phosphorus to encourage more blooms.
Deadheading
To keep your cannas looking neat and to encourage the plant to produce more flowers, you should practice "deadheading." This simply means removing the flowers once they have faded.
When a flower cluster has finished blooming, look further down the stem for a new bud that is starting to form. Cut the old flower stalk off just above that new bud. Once the entire stalk has finished producing buds, you can cut that individual stalk back to the foliage level. This prevents the plant from wasting energy on seed production and keeps the focus on new growth.
Key Takeaway: Cannas are thirsty and hungry! Consistent watering and regular feeding are the "secret" to reaching those impressive heights.
Handling Common Pests and Challenges
Cannas are generally very tough, but like all garden plants, they can occasionally face challenges. Most issues are easy to manage if you catch them early and follow the right approach.
Canna Leaf Rollers
The most common pest for cannas is the leaf roller, which is the larva of a small moth. As the name suggests, these tiny caterpillars use silk to roll the canna leaves into a tube, where they hide and feed. You might notice small holes in the leaves or see a leaf that refuses to unfurl.
The best way to handle these is to unroll the leaf by hand and remove the caterpillar, or simply prune off the affected leaf and dispose of it. For larger infestations, some gardeners use an organic spray containing Bacillus thuringiensis (Bt), which is a naturally occurring soil bacterium that targets caterpillars.
Fungal Issues
In very humid climates or if plants are spaced too closely together, cannas can sometimes develop fungal spots on their leaves. This is usually more of an aesthetic issue than a health threat to the plant. To keep your cannas looking their best, always water at the base of the plant rather than over the leaves, and ensure there is enough space between plants for air to circulate.
Troubleshooting Slow Growth
If your cannas aren't growing as fast as you expected, it is almost always due to one of three things:
- Cold Soil: If the ground hasn't warmed up yet, the rhizome will stay dormant.
- Lack of Water: Cannas will "stall" if they get too dry.
- Too Much Shade: They need that direct sun to power their growth.
If you adjust these factors, you will usually see a quick response from the plant.
Overwintering Cannas: Protecting Your Investment
In USDA zones 7 through 10, cannas are hardy and can stay in the ground all winter. In these warmer areas, simply cut the foliage back to about 4 inches above the ground after the first frost and apply a thick layer of mulch to provide a little extra insulation.
However, if you live in zone 6 or colder, the winter freeze will kill the rhizomes if they are left in the ground. You can treat cannas as annuals and buy fresh rhizomes each year, or you can "lift" and store them.
Lifting Rhizomes in the Fall
Wait until the first frost has blackened the foliage. This signals to the plant that it is time to go dormant.
- Cut the stems back to about 4 to 6 inches.
- Gently lift the clumps of rhizomes with a garden fork, being careful not to bruise or cut them.
- Shake off the excess soil and let them sit in a dry, shaded area (like a garage or shed) for a few days to "cure."
Winter Storage
Place the cured rhizomes in a cardboard box or a plastic bin filled with slightly damp peat moss, vermiculite, or sawdust. Store the container in a cool, dark, frost-free place, such as a basement or crawl space. The ideal temperature is between 40°F and 50°F. Check on them once or twice during the winter; if the rhizomes look shriveled, lightly mist the packing material with water. If you see any soft or rotting spots, remove those pieces immediately to keep the rest healthy.
If you want to read more about company policies and support, Longfield Gardens’ Our Guarantee page explains its 100% quality guarantee. (longfield-gardens.com)
Designing with Cannas
Because cannas are so tall and colorful, they offer endless possibilities for garden design. Here are a few ways we like to use them:
- Privacy Screens: Plant a long row of tall green or bronze-leaved cannas along a property line. Within two months, you'll have a living wall that blocks the view and adds beautiful texture.
- The "Tropical Corner": Group cannas with other large-leaved plants like elephant ears (Colocasia) and hibiscus. This creates a high-impact "jungle" look that feels like an escape from the ordinary.
- Back-of-the-Border Drama: Use cannas as a backdrop for shorter sun-loving perennials like coneflowers, black-eyed Susans, or ornamental grasses. The cannas provide the height, while the perennials fill in the middle ground.
- Entryway Statements: Place two large pots of cannas on either side of a front door or garden gate for a grand, welcoming entrance.
The Learn section is a good next stop if you want more how-to and inspiration content for summer-blooming bulbs. (longfield-gardens.com)
Why We Love Cannas
At Longfield Gardens, we see cannas as the ultimate "effort-to-impact" plant. There aren't many other plants that can grow from a modest rhizome to a towering floral giant in such a short window of time. They are resilient, adaptable, and bring a sense of fun and adventure to the landscape.
When you plant cannas, you aren't just adding a flower to your garden; you are adding architecture and personality. Whether you choose a classic red-flowered variety with green leaves or a modern hybrid with multi-colored foliage, you are guaranteed a summer full of color.
Summary Checklist for Canna Success
- Site: Choose full sun (6+ hours) and rich, moist soil.
- Timing: Plant when the soil reaches 60°F and frost is a distant memory.
- Planting: 4 inches deep, eyes up, spaced 18-24 inches apart.
- Water: Keep the soil consistently moist—don't let them dry out.
- Food: Feed with a balanced fertilizer every few weeks.
- Winter: In cold zones, lift and store rhizomes after the first frost.
Gardening should always feel like a rewarding hobby rather than a series of rules. Cannas are the perfect partner for this philosophy because they are so willing to grow and bloom with just a little bit of care.
We invite you to browse the many beautiful varieties of canna rhizomes we offer and start planning your tropical oasis today. The Canna Tall Tropicanna page is a great example of the bold foliage available. (longfield-gardens.com)
FAQ
When is the best time to plant cannas?
The best time to plant canna rhizomes is in the spring once the soil has warmed to about 60°F and there is no longer any danger of frost. In most regions, this is around the same time you would plant warm-weather vegetables like tomatoes. If you plant them too early in cold, wet soil, the rhizomes may rot or simply stay dormant until the weather warms up.
Do cannas need a lot of water?
Yes, cannas are one of the most moisture-loving plants in the garden. They thrive in soil that is kept consistently moist and can even tolerate "wet feet" in boggy areas. During the hottest parts of the summer, you should check the soil daily and provide a deep soaking whenever the top inch of soil feels dry. Mulching around the base of the plant is a great way to help the soil retain this necessary moisture.
Can I grow cannas in pots?
Cannas are excellent for containers and can bring a dramatic vertical element to patios or balconies. Because they grow quite large, you should choose a sturdy pot that is at least 12 to 18 inches in diameter. Be sure to use a high-quality potting mix and keep a close eye on the watering, as container-grown plants dry out much faster than those in the ground. For more inspiration, the Summer Blooming Bulbs for Containers page shows additional container-friendly options. (longfield-gardens.com)
Do I have to dig up my cannas in the winter?
This depends on your USDA hardiness zone. If you live in zone 7 or warmer, cannas are generally hardy and can stay in the ground year-round with a layer of protective mulch. If you live in zone 6 or colder, the winter temperatures will likely kill the rhizomes. In these areas, you should dig them up after the first frost, let them dry, and store them in a cool, frost-free place until the following spring.
If you need help with orders or shipping timing, the Shipping Information page is the best place to start. (longfield-gardens.com)