Table of Contents
- Introduction
- Understanding the Nature of Canna Lilies
- The Role of Growing Zones
- Planting for Long-Term Success
- Summer Care to Build Strong Rhizomes
- How to Overwinter Cannas in Cold Climates
- Dividing Cannas for More Plants
- Growing Cannas in Containers
- Choosing Varieties for Performance
- Common Questions About Perennial Success
- Summary of Yearly Canna Care
- Conclusion
- FAQ
Introduction
There is nothing quite like the sight of a canna lily hitting its stride in the heat of midsummer. With their massive, paddle-shaped leaves and vibrant, tropical blooms, these plants transform any backyard into an exotic retreat. Whether you love the dramatic height they add to a border or the way their neon-bright flowers attract hummingbirds, cannas are a favorite for gardeners who want big results with simple care.
At Longfield Gardens, we enjoy helping people discover how easy it is to bring this tropical flair to their own landscapes with our Assorted Cannas.
This guide will explain the perennial nature of canna lilies and provide clear steps for keeping them healthy season after season. You will learn how to identify your growing zone with the USDA Plant Hardiness Zone Map, how to handle winter storage, and the best ways to ensure a spectacular display every summer. Canna lilies are indeed perennials, but their success depends on matching their tropical needs with your local climate.
Understanding the Nature of Canna Lilies
To answer if canna bulbs are perennial, we first have to look at what these plants actually are. Biologically, cannas are tropical and subtropical perennials. This means that in their natural habitat, they grow, bloom, and stay alive for many years. Unlike an annual plant that completes its entire life cycle in one season and then dies, a canna is designed to persist.
However, gardeners often use the term "bulb" as a catch-all for any plant with a fleshy root. Technically, cannas grow from rhizomes. A rhizome is a thick, horizontal underground stem that stores energy for the plant. Because they store so much fuel in these rhizomes, cannas are remarkably resilient. For more background, see All About Cannas.
In the United States, whether a canna acts like a perennial in your garden depends on the winter. In warm regions, they are "hardy" and stay in the ground year-round. In colder regions, they are considered "tender perennials." This means the plant wants to live for many years, but it cannot survive a deep freeze. For gardeners in the north, keeping them as perennials simply requires a little bit of extra care in the fall.
The Role of Growing Zones
The USDA Plant Hardiness Zone Map is the most helpful tool for determining how your cannas will behave. Because cannas are native to warm, humid climates, they have a specific threshold for cold.
Warm Climates (Zones 7 to 11)
In most parts of the southern United States, cannas are reliably perennial without much intervention. In zones 8 through 11, the ground rarely freezes deep enough to damage the rhizomes. In these areas, you can leave the rhizomes in the soil all year. They will go dormant when the temperature drops, and the foliage may die back to the ground, but the "bulb" remains safe beneath the surface.
Transition Zones (Zone 7)
Zone 7 is often considered the "tipping point" for cannas. In a mild winter, cannas left in the ground with a thick layer of mulch will often return. However, a particularly harsh winter with a deep freeze can be tough on them. Many gardeners in this zone choose to lift their rhizomes just to be safe, while others rely on heavy mulching to insulate the soil.
Cold Climates (Zones 3 to 6)
If you live in the Midwest, the Northeast, or the mountain regions, cannas will not survive the winter outdoors. The frozen soil will cause the moisture-rich rhizomes to turn to mush. In these zones, you have two choices: treat them as annuals and buy new ones each spring, or "lift" the rhizomes in the autumn to store them indoors. Most gardeners find that lifting them is a rewarding way to keep their favorite varieties going year after year.
Key Takeaway: Cannas are perennials by nature, but they are only "winter-hardy" in warmer climates. Knowing your USDA zone helps you decide whether to leave them in the ground or bring them inside for the winter.
Planting for Long-Term Success
If you want your cannas to return with vigor each year, the process starts with proper planting in the spring. A healthy, well-fed plant creates a larger, stronger rhizome. The more energy the rhizome stores during the summer, the better it will perform the following year.
Choosing the Right Spot
Cannas are sun-worshippers. To get the best growth and the most flowers, place them in a spot that receives at least six to eight hours of direct sunlight. For tall, dramatic plantings, browse Tall Cannas. While they can grow in partial shade, they often become "leggy"—stretching toward the light—and produce fewer blooms. Sunlight is the fuel that allows the rhizome to grow and multiply underground.
Soil and Drainage
While cannas are famous for loving moisture, they do not like to sit in stagnant, soggy puddles. The best soil is rich in organic matter and drains well. If your soil is heavy clay, adding some compost or peat moss can help improve the texture. For those with very wet areas, cannas are actually one of the few decorative plants that can handle "wet feet" better than most, but for the purpose of overwintering, good drainage is still a plus.
Planting Depth and Spacing
When the soil has warmed up to at least 65°F in the spring, it is time to plant. Follow these simple steps for the best results:
- Depth: Plant the rhizomes about 2 to 3 inches deep.
- Orientation: Lay the rhizome horizontally in the hole. If you see small "eyes" or points of growth, face them upward.
- Spacing: Give them room to breathe. Space Medium Cannas about 1 foot apart, and tall varieties about 2 feet apart.
- Watering: Water them well right after planting to settle the soil around the roots.
Summer Care to Build Strong Rhizomes
Because you want your cannas to be perennial, summer care is about more than just looking at the flowers. It is about building a "battery" in the rhizome. A plant that is stressed by drought or lack of nutrients will have a smaller, weaker rhizome by the end of the season.
Water Consistently
Cannas are thirsty plants. They have large leaves that lose a lot of moisture through evaporation, especially on hot, breezy days. Keep the soil consistently moist. If you are growing cannas in containers, you may need to water them every day during the peak of summer. For more container-specific advice, see How Many Canna Bulbs Per Container?.
Fertilizing for Growth
Since cannas grow so fast—some reaching 6 or 8 feet in just a few months—they need plenty of food. A monthly application of a balanced liquid fertilizer or a slow-release granular food in the spring will keep them pushing out new foliage and flowers. This extra nutrition ensures the rhizome grows large enough to be divided later.
Deadheading
To keep the plant focused on growth rather than producing seeds, remove the spent flowers. This is called deadheading. Cut the flower stalk down to the next visible bud or leaf. This keeps the plant looking tidy and encourages more blooms to form throughout the season.
What to do next:
- Monitor soil moisture during heat waves.
- Apply a balanced fertilizer once a month.
- Snip off faded flowers to keep the plant's energy focused on growth.
- Keep an eye out for "canna leaf rollers" and remove damaged leaves if necessary.
How to Overwinter Cannas in Cold Climates
If you live in a zone where the ground freezes, you can still enjoy your cannas as perennials by "lifting" them. This is the process of digging up the rhizomes and keeping them in a dormant state until spring. It sounds technical, but it is a straightforward afternoon project.
When to Dig
Wait for the first frost of the autumn. The cold will turn the lush green leaves to a dark brown or black. This is actually helpful, as it signals to the plant that it is time to go dormant. You do not need to rush out the very second it frosts, but try to get them out of the ground before a hard freeze sets in.
The Lifting Process
First, cut the stalks down so only about 2 to 4 inches of stem remain above the ground. Use a garden fork or a shovel to gently loosen the soil around the plant. Be careful to give the plant a wide berth so you don't accidentally slice through the rhizomes. Once the soil is loose, lift the entire clump out of the ground.
Cleaning and Curing
Shake off the excess soil. You don't need to scrub them perfectly clean; a little bit of dirt is fine. Let the rhizomes sit in a dry, shaded, frost-free area for a few days. This is called "curing." It allows the outer skin to toughen up slightly, which helps prevent rot during storage.
Storage Conditions
Once cured, place the rhizomes in a container. A cardboard box, a plastic bin with air holes, or a paper bag works well. To keep the rhizomes from drying out completely, many gardeners pack them in slightly damp peat moss, perlite, or vermiculite.
- Temperature: Store the box in a cool, dark place that stays between 40°F and 50°F. An unheated basement, a crawl space, or a cool closet usually works perfectly.
- Check-ins: Once or twice during the winter, peek inside the box. If the rhizomes look shriveled, a tiny spritz of water can help. If any look soft or molded, remove them immediately so they don't affect the others.
Dividing Cannas for More Plants
One of the best things about cannas being perennial is that they don't just survive—they multiply. Over a single growing season, one rhizome can grow into a large clump with many "eyes." Dividing these clumps is the easiest way to get more plants for free.
The best time to divide is in the spring, just before you are ready to plant them again. If you kept your clumps whole over the winter, they are usually easier to manage in the spring. Look for the "eyes"—the small, pointed bumps where new stems will grow.
Using a clean, sharp knife or even your hands, break the large clump into smaller sections. Each new piece should have at least two or three healthy eyes and a good portion of the fleshy rhizome attached. Let the cut ends dry for a few hours before putting them back in the dirt. This simple step ensures that your garden grows more beautiful and lush every single year.
Growing Cannas in Containers
If the idea of digging up plants every fall feels like a lot of work, growing cannas in pots is a great alternative. For a practical step-by-step look, see Can Canna Bulbs Be Planted in Pots?.
In the spring, plant your rhizomes in a large, sturdy container with good drainage holes. Use a high-quality potting mix. Because cannas grow quite tall and have heavy leaves, a heavy pot (like ceramic or a large resin planter) is better than a light plastic one that might tip over in the wind. For broader container-growing tips, see How to Grow Summer Bulbs in Containers.
When the first frost hits in the fall, simply cut the foliage back and move the entire pot into a frost-free garage or basement. You don't even have to take the rhizomes out of the soil. The soil in the pot acts as insulation. In the spring, move the pot back outside, start watering again, and the cannas will wake up and begin their new season of growth.
Choosing Varieties for Performance
Since you plan on keeping these plants for years, it is worth choosing varieties that you truly love. Cannas come in a wide range of colors and sizes.
- Dwarf Varieties: These stay around 2 to 3 feet tall. They are excellent for the front of a border or for smaller containers on a patio. Medium Cannas are an excellent fit.
- Tall Varieties: These can reach 5 to 8 feet. They create a wonderful "living screen" or a dramatic backdrop for shorter flowers. Tall Cannas are a strong choice for that effect.
- Foliage Types: Don't just look at the flowers! Some cannas have deep burgundy or bronze leaves that look stunning even when the plant isn't blooming. Others have variegated leaves with stripes of green, yellow, and white.
When you buy your rhizomes, look for ones that are plump and firm. At Longfield Gardens, we make sure our rhizomes are "graded" for quality. A larger rhizome with more eyes will always give you a faster start and a more impressive plant in its first year.
Common Questions About Perennial Success
Even though cannas are easy to grow, a few common situations might make you wonder about their perennial status.
Why didn't my cannas come back?
If you live in a warm zone and your cannas didn't return, the most likely culprit is "wet feet" during the winter. If the soil stays saturated and cold for a long time, the rhizomes can rot. Improving drainage or planting on a slight mound can help. In cold zones, the most common reason is that the storage area got too cold (freezing the rhizome) or too warm (causing it to sprout too early and exhaust its energy).
Do I need to soak the bulbs?
While not strictly necessary, soaking your canna rhizomes in lukewarm water for a few hours before planting can "wake them up." It hydrates the tissue and can lead to slightly faster sprouting once they are in the ground.
Can I grow them from seed?
You can, but it is a much slower process. Most gardeners prefer rhizomes because you get a full-sized, blooming plant in the very first season. Plants grown from seed may take a few years to reach their full potential and may not look exactly like the parent plant.
Are cannas safe for pets?
Yes! One of the wonderful things about cannas is that they are non-toxic to dogs, cats, and horses. This makes them a worry-free choice for family gardens.
Key Takeaway: Success with cannas as perennials comes down to three things: plenty of summer sun, consistent water, and protecting the rhizome from freezing temperatures in the winter.
Summary of Yearly Canna Care
Keeping cannas as perennials is a simple cycle. By following these steps, you can enjoy the same plants for a decade or more.
- Spring: Divide your rhizomes and plant them in warm soil (65°F+) after the danger of frost has passed.
- Summer: Provide full sun, plenty of water, and monthly fertilizer to build a strong "bulb."
- Autumn: In cold zones, lift the rhizomes after the first frost. In warm zones, mulch heavily and leave them in place.
- Winter: Store lifted rhizomes in a cool, dark, dry place (40-50°F) and check them occasionally for health.
Conclusion
Canna lilies are some of the most rewarding plants you can add to your garden. Their bold textures and vibrant colors bring a sense of joy and excitement that few other plants can match. Whether you live in the sunny South or the snowy North, you can absolutely enjoy these tropical beauties as perennials. By understanding your growing zone and giving the rhizomes a little bit of winter protection, you ensure that your garden will be filled with lush, tropical energy year after year.
We at Longfield Gardens are proud to provide high-quality rhizomes that help you get a head start on a beautiful season. With just a few simple steps, you can turn a single planting into a lifetime of summer blooms.
- Check your USDA zone to decide on your winter strategy.
- Give your cannas the sun and water they crave for maximum growth.
- Store or mulch your rhizomes properly to guarantee a return performance.
"Gardening is a rewarding journey, and canna lilies are the perfect companions for those who want big, tropical beauty with reliable results every single year."
Ready to start your own tropical oasis? We offer a wide selection of premium canna rhizomes to help you create a stunning, perennial display in your own backyard.
FAQ
Do canna lilies come back every year?
Yes, canna lilies are perennials and will return every year as long as the underground rhizome is protected from freezing. In USDA zones 8 to 11, they can stay in the ground year-round. In zones 3 to 7, the rhizomes must be dug up in the fall and stored indoors to survive the winter.
What is the difference between a canna bulb and a rhizome?
While people often call them "bulbs," cannas actually grow from rhizomes, which are thick, fleshy underground stems. Unlike true bulbs (like tulips) which have layers, rhizomes grow horizontally and store energy to produce new stems and roots. This structure allows them to be easily divided to create new plants.
When should I dig up my canna rhizomes for the winter?
You should dig up your canna rhizomes shortly after the first frost in the autumn has killed the foliage. The frost turns the leaves brown, signaling the plant to go dormant. It is important to lift them before the ground freezes solid, as freezing temperatures will damage or kill the rhizomes.
Can I leave cannas in pots over the winter?
Yes, if you grow cannas in containers, you can leave them in the pots for the winter. After the first frost, cut the stems back to a few inches, move the entire pot to a cool, frost-free area like a basement or garage, and stop watering. In the spring, you can move the pot back outside and resume watering to wake the plants up.