Do Canna Lilies Have Bulbs?

Table of Contents

1. Introduction
2. Defining the Canna "Bulb"
3. Why the Difference Between Bulbs and Rhizomes Matters
4. The Physical Anatomy of a Canna Rhizome
5. How Cannas Multiply Underground
6. Matching Cannas to the Right Spot
7. Planting Your Canna Rhizomes
8. Water and Fertilizer Needs
9. Caring for Cannas in Different Climates
10. How to Overwinter Canna Rhizomes
11. Dividing Canna Rhizomes for More Plants
12. Growing Cannas in Containers
13. Realistic Expectations for Your Cannas
14. Canna Varieties for Every Style
15. Conclusion
16. FAQ

Introduction

Few plants bring a sense of tropical flair to the backyard like canna lilies. With their bold, paddle-shaped leaves and brilliant flowers in shades of red, orange, yellow, and pink, they are a favorite for anyone looking to add high-impact color and height to their summer garden. Whether you are planting a single specimen in a patio pot or a lush border along a sunny fence, cannas offer a rewarding experience for gardeners of all skill levels. (longfield-gardens.com)

At Longfield Gardens, we enjoy helping home gardeners find success with these vibrant plants. If you have ever held a "canna bulb" in your hand and wondered why it looks more like a ginger root than a tulip, you are asking a great question. While they are often sold and labeled as bulbs for simplicity, there is a bit more to the story of how these plants grow underground. (longfield-gardens.com)

This article explains the physical structure of canna lilies, clarifies the difference between bulbs and rhizomes, and provides practical steps for planting and caring for them. Understanding how canna lilies grow from their fleshy roots is the key to ensuring they return with more vigor and beauty every summer. (longfield-gardens.com)

Defining the Canna "Bulb"

If you head to a garden center or browse our selection online, you will likely see cannas listed in the Spring-Planted Bulbs category. However, if you want to be botanically accurate, canna lilies do not actually have bulbs. Instead, they grow from a structure called a rhizome. (longfield-gardens.com)

A rhizome is a thick, fleshy underground stem that grows horizontally just beneath the soil surface. While a "true bulb" like a tulip or onion is made up of layered fleshy leaves, a rhizome is a solid, continuous piece of plant tissue. Think of it as the plant's underground energy warehouse. It stores the starches and nutrients the plant needs to push out those massive leaves and tall flower spikes during the heat of summer. (longfield-gardens.com)

Because rhizomes are essentially stems, they have nodes, which are often called "eyes." These are the small, pointed buds from which new shoots and roots will grow. When you look at a canna rhizome, you might see several of these eyes poking out from the surface. Each eye has the potential to become a whole new plant, which is why cannas are so easy to multiply over time. (longfield-gardens.com)

Why the Difference Between Bulbs and Rhizomes Matters

You might wonder why we make the distinction between a bulb and a rhizome if the end result is a beautiful flower. For the home gardener, understanding this difference helps with two main tasks: planting and propagation. (longfield-gardens.com)

True bulbs, like daffodils or lilies, are usually planted quite deep—often three times the height of the bulb itself. They grow vertically and generally stay in the same spot, slowly producing tiny "bulblets" around their base. They are self-contained packages designed to survive deep in the cool earth. (longfield-gardens.com)

Rhizomes, however, like to stay closer to the surface. Because they are underground stems, they need to be planted shallowly so the new shoots can easily reach the light. Furthermore, because they grow horizontally, cannas will naturally spread out and colonize a larger area over a single growing season. Knowing this helps you plan your garden spacing, giving the cannas enough room to expand their underground "footprint" without crowding out neighboring perennials. (longfield-gardens.com)

Key Takeaway: While commonly called bulbs, canna lilies grow from rhizomes, which are horizontal underground stems. Planting them shallowly allows their "eyes" to sprout quickly and reach the sun.

The Physical Anatomy of a Canna Rhizome

When your order from Longfield Gardens arrives, your canna rhizomes will look like firm, chunky pieces of root. They are usually tan or light brown on the outside and may feel surprisingly heavy for their size. This weight comes from the moisture and stored energy inside. (longfield-gardens.com)

Here is what to look for when inspecting your canna rhizomes:

• The Eyes: These are the most important part. They look like small, pointed bumps or buds. Some might already be showing a bit of green or pinkish growth.
• The Flesh: The body of the rhizome should be firm to the touch. If you were to snap one in half, the inside would look white and starchy, similar to a potato.
• The Skin: The outer layer is often slightly papery or rough, which helps protect the fleshy interior from drying out or being damaged by soil-borne insects.

If a rhizome feels light or hollow, it has likely dried out too much. On the other hand, it should never feel mushy or soft. Starting with firm, healthy rhizomes is the easiest way to ensure a successful growing season. (longfield-gardens.com)

How Cannas Multiply Underground

One of the most exciting aspects of growing canna lilies is how much they grow below the soil. When you plant one single rhizome in the late spring, it doesn't just sit there. As the plant grows taller and produces flowers, it is also busy sending out new horizontal shoots underground. (longfield-gardens.com)

By the end of the summer, that one original rhizome may have grown into a large, interconnected clump of several new rhizomes. In many cases, a single plant can turn into five or six new ones by the time the first frost arrives. This vigorous growth habit makes cannas an excellent value for the gardener. If you take care of them and store them properly in colder climates, you will have a much larger supply of plants to work with every year. (longfield-gardens.com)

Matching Cannas to the Right Spot

Success starts with the "right plant, right place" rule. Since cannas are tropical in origin, they have a few specific preferences that will help them perform their best. (longfield-gardens.com)

Sun Requirements

Cannas are sun-worshippers. To produce those vibrant, saturated flower colors and maintain strong, upright stems, they need plenty of direct light. Aim for a spot that gets at least six to eight hours of full sun every day. If they are planted in too much shade, they tend to become "leggy" (tall and weak) and may produce fewer flowers. (longfield-gardens.com)

Soil and Drainage

While cannas love moisture, they do not like to sit in stagnant, waterlogged soil, which can cause the rhizomes to rot. They prefer rich, loamy soil that is high in organic matter. If your soil is heavy clay, you can improve the drainage and texture by mixing in some compost or well-rotted manure before planting. (longfield-gardens.com)

In very sandy soil, the water might drain away too quickly. In this case, adding organic matter helps the soil hold onto the moisture the plants need to support their large, lush leaves. (longfield-gardens.com)

Planting Your Canna Rhizomes

Once the danger of frost has passed and the soil has warmed up to at least 60°F, it is time to get your cannas in the ground. Planting too early in cold, wet soil can lead to slow growth or rotting, so patience is rewarded. (longfield-gardens.com)

Steps for Planting:

1. Dig a shallow hole: You only need to go about 4 to 6 inches deep.
2. Position the rhizome: Lay the rhizome horizontally in the hole. If you can see the "eyes" or buds, point them upward. If it is hard to tell which way is up, don't worry—the plant is smart enough to find the light and grow toward the surface regardless.
3. Spacing: Space your rhizomes about 1 to 2 feet apart. Remember, they will spread horizontally throughout the summer, so giving them room now prevents overcrowding later.
4. Cover and Water: Cover the rhizome with 2 to 3 inches of soil. Press down lightly to remove any large air pockets, and then water the area thoroughly to settle the soil around the plant.

Next Steps for Success:

• Wait for the soil to warm up before planting out.
• Plant rhizomes horizontally, 2 to 3 inches deep.
• Give each plant at least 12 to 18 inches of space to expand.
• Water well immediately after planting.

Water and Fertilizer Needs

Canna lilies are "heavy feeders," meaning they use a lot of energy and nutrients to produce their massive foliage and flowers. Because they have such large leaves, they also lose water through transpiration more quickly than many other garden plants. (longfield-gardens.com)

Watering Rules

The goal for cannas is consistent moisture. During the heat of the summer, you may need to water them every few days, or even daily if they are in containers. A deep soaking once or twice a week is usually better than a light sprinkling every day, as it encourages the roots to grow deeper into the soil. If the edges of the leaves start to turn brown or "burn," it is often a sign that the plant is thirsty. (longfield-gardens.com)

Fertilizing for Blooms

To keep the flowers coming all summer, we recommend using a balanced, all-purpose fertilizer. You can apply a slow-release fertilizer at planting time, or use a liquid fertilizer once a month throughout the growing season. Follow the instructions on the product label for the correct amounts. Healthy, well-fed plants are more resistant to pests and can better withstand the stress of mid-summer heatwaves. (longfield-gardens.com)

Caring for Cannas in Different Climates

Whether you need to dig up your canna rhizomes in the fall depends entirely on your USDA hardiness zone. Cannas are tropical plants and cannot survive temperatures that freeze the ground. For a quick reference, see the USDA Hardiness Zone Map. (longfield-gardens.com)

Tropical and Warm Climates (Zones 8-11)

In these areas, cannas are perennial. You can leave the rhizomes in the ground year-round. After the foliage dies back in late autumn or after a light frost, simply cut the stems down to the ground. You might choose to add a few inches of mulch over the top to protect the soil from temperature swings. Every three or four years, it is a good idea to dig up the clumps and divide them to prevent them from becoming too crowded. (longfield-gardens.com)

Cooler Climates (Zones 7 and Below)

In these regions, cannas are treated as "tender perennials." This means they will thrive in the summer but must be protected from the winter cold. You have two choices: treat them as annuals and buy new rhizomes each spring, or dig them up and store them indoors for the winter. Most gardeners find that overwintering is a fun and rewarding way to build a large collection of plants over time. (longfield-gardens.com)

How to Overwinter Canna Rhizomes

If you live in a climate where the ground freezes, follow these steps to keep your cannas safe until next year. For shipping and timing details, check the Shipping Information page. (longfield-gardens.com)

Timing the Harvest

Wait until the first light frost has hit your garden. You will notice the lush green leaves turn black or brown almost overnight. This frost is actually helpful; it signals to the plant that it is time to go dormant and move all its energy down into the rhizome. Do not wait for a "hard freeze" that penetrates the ground, as this can damage the fleshy rhizomes. (longfield-gardens.com)

Digging and Cleaning

1. Cut back the stalks: Use garden shears to cut the stems down to about 2 or 3 inches above the soil line.
2. Lift carefully: Use a garden fork or a shovel to gently lift the clump out of the ground. Start digging a few inches away from the base of the plant to avoid slicing into the rhizomes.
3. Shake off the soil: Gently shake the clump to remove most of the dirt. You can also rinse them with a garden hose if the soil is very sticky, but be careful not to scrub them, as the skin is delicate when wet. (longfield-gardens.com)

Curing the Rhizomes

Before you put your cannas into storage, they need to "cure." This means letting them air-dry for about a week in a protected, frost-free area like a garage or a shed. Curing allows the outer skin to toughen up, which helps prevent rot and mold during the long winter months. (longfield-gardens.com)

Winter Storage

Once cured, place the rhizomes in a cardboard box, a plastic bin with air holes, or a paper bag. To keep the moisture levels balanced, nestle them in a bedding of peat moss, vermiculite, or even shredded newspaper. You want them to stay dry enough that they don't rot, but not so dry that they shrivel up completely. (longfield-gardens.com)

Store the container in a cool, dark place where the temperature stays between 40°F and 50°F. A basement, crawl space, or an insulated garage is usually perfect. Check on them once a month; if they look shriveled, give them a very light misting of water. (longfield-gardens.com)

Key Takeaway: In cold zones, dig up canna rhizomes after the first frost, cure them for a week, and store them in a cool, dark place in peat moss or newspaper.

Dividing Canna Rhizomes for More Plants

Spring is the best time to divide your canna clumps. When you bring your rhizomes out of storage (or dig them up in warm zones), you will likely see that the clump has grown quite large. (longfield-gardens.com)

To divide them, use a clean, sharp knife to cut the rhizome into smaller sections. Each section must have at least one or two healthy "eyes" (buds). Let the cut ends dry and "callous" over for a day or two before planting. This simple process allows you to turn one large clump into several new plants to share with friends or to fill new corners of your garden. (longfield-gardens.com)

Growing Cannas in Containers

If you have a small garden or only a balcony, you can still enjoy cannas. In fact, growing them in pots is one of the easiest ways to manage them. For more container basics, see How to Grow Summer Bulbs in Containers. (longfield-gardens.com)

Selecting a Pot

Choose a large container with plenty of drainage holes at the bottom. A pot that is at least 12 inches in diameter is a good start for a single plant. Larger Tall Cannas will need even more space and a heavier pot to prevent them from tipping over in the wind. (longfield-gardens.com)

Container Care

Plants in containers dry out much faster than those in the ground. You will need to monitor the moisture daily during the summer. Since the nutrients in potting soil are washed away with frequent watering, regular fertilizing is essential for container-grown cannas. (longfield-gardens.com)

Winter Storage for Pots

If you grow cannas in pots in a cold climate, you don't necessarily have to dig them up. You can simply cut the foliage back to the soil line after the first frost and move the entire pot into a frost-free garage or basement. In the spring, move the pot back outside, start watering, and the rhizomes will wake up and begin to grow again. (longfield-gardens.com)

Realistic Expectations for Your Cannas

While canna lilies are generally very easy to grow, it is important to remember that they are living things influenced by their environment. (longfield-gardens.com)

• Bloom Timing: Most cannas begin blooming in mid to late summer and continue until the first frost. If your summer is particularly cool or cloudy, they may take a bit longer to start flowering. (longfield-gardens.com)
• Size: The height listed on the tag is an estimate. In very rich soil with plenty of water, a canna might grow taller than expected. In poor soil or high wind, it might stay a bit shorter. (longfield-gardens.com)
• Pests: In some regions, canna leaf rollers (small caterpillars) can be an issue. They roll themselves up in the leaves and nibble on the foliage. Simply keeping an eye on your plants and removing affected leaves or manually picking off the pests is usually enough to keep the plant healthy. (longfield-gardens.com)

Canna Varieties for Every Style

When choosing cannas, consider both the flowers and the foliage. Some varieties are grown specifically for their dramatic leaves, which can be solid green, deep burgundy, or even striped with yellow and white. For a dramatic striped example, try Canna Tall Pretoria. (longfield-gardens.com)

• Dwarf Cannas: These usually stay under 3 feet tall, making them perfect for the front of a border or for smaller containers. If you want a compact option, browse Short Cannas. (longfield-gardens.com)
• Tall Cannas: Some varieties can reach 6 to 8 feet in height. These create a fantastic living privacy screen or a bold backdrop for shorter flowers. You can shop Canna Tall Tropicanna, Canna Tall Stuttgart, and the Tall Cannas collection. (longfield-gardens.com)
• Variegated Foliage: If you want interest even when the plant isn't blooming, look for varieties with multi-colored leaves. They look beautiful even before the first flower bud appears. Another good choice is Canna Tall Tropicanna Gold. (longfield-gardens.com)

Conclusion

Canna lilies are a fantastic addition to any summer garden, offering a unique blend of tropical foliage and vibrant flowers. While they are often called bulbs, knowing that they are actually rhizomes helps you understand how they grow, spread, and store energy. By providing them with plenty of sun, consistent water, and a little bit of winter protection in colder zones, you can enjoy these spectacular plants for many years. (longfield-gardens.com)

• Plant rhizomes in warm soil after the danger of frost.
• Select a sunny location with well-draining, rich soil.
• In cold climates, dig and store the rhizomes over the winter.
• Divide clumps in the spring to multiply your collection.

We hope this guide helps you feel confident as you bring the beauty of cannas into your own backyard. Whether you are a beginner or an experienced gardener, cannas are a reliable way to create a more beautiful landscape. For the best results, start with high-quality rhizomes from us at Longfield Gardens and enjoy the tropical transformation of your garden. (longfield-gardens.com)

FAQ

Is a canna lily a bulb or a perennial?

Botanically, a canna lily grows from a rhizome, which is a fleshy underground stem, rather than a true bulb. In warm climates (zones 8 and above), cannas are perennials that stay in the ground year-round. In colder climates, they are considered tender perennials that must be dug up and stored indoors over the winter to survive. (longfield-gardens.com)

Which way is up when planting a canna lily rhizome?

Canna rhizomes should be planted horizontally, about 2 to 3 inches deep. If you can see the "eyes" or small pointed growth buds, try to point them upward toward the sky. However, don't worry if you aren't sure; the plant will naturally sense the warmth of the sun and send its shoots upward through the soil. (longfield-gardens.com)

Do I have to dig up my canna bulbs every year?

Whether you need to dig them up depends on where you live. If your garden is in USDA zone 8 or warmer, you can safely leave them in the ground. If you live in zone 7 or colder, the ground will freeze deep enough to kill the rhizomes, so you should dig them up after the first frost if you want to save them for next year. (longfield-gardens.com)

Can I grow canna lilies in pots?

Yes, canna lilies perform very well in containers. Because they can grow quite large, choose a sturdy pot at least 12 inches in diameter with good drainage. Container-grown cannas require more frequent watering and regular fertilizing than those planted in the ground, but they are a great way to add height and color to a patio or balcony. (longfield-gardens.com)