Dividing Canna Lily Bulbs for a Lush Summer Garden

Table of Contents

1. Introduction
2. Why You Should Divide Canna Lily Bulbs
3. The Best Time for Division
4. Tools You Will Need
5. Step 1: Lifting the Clumps
6. Step 2: Cleaning and Inspection
7. Step 3: Identifying the "Eyes"
8. Step 4: How to Divide the Rhizomes
9. Step 5: Curing the Divisions
10. Step 6: Planting Your New Divisions
11. Dividing Cannas in Containers
12. Caring for Your New Divisions
13. Common Canna Varieties to Divide
14. Storing Divisions for the Winter
15. Summary of the Division Process
16. Conclusion
17. FAQ

Introduction

Few plants bring as much drama and tropical flair to the backyard as the canna lily. With their oversized, paddle-like leaves and brilliant blooms in shades of red, orange, yellow, and pink, they turn any garden bed into a vacation-like retreat. At Longfield Gardens, we love how these vigorous growers can transform a landscape in just one season. Whether you are growing them in large decorative pots or as a privacy screen along a fence, cannas are some of the most rewarding plants for a sunny spot. (longfield-gardens.com)

As cannas grow, they naturally expand underground. What started as a single plant can quickly become a large, crowded clump. This is actually a wonderful problem to have, as it means you have plenty of material to create even more beauty. Dividing canna lily bulbs—which are technically called rhizomes—is the easiest way to multiply your collection and keep your original plants healthy and productive. This guide will walk you through the simple process of lifting, cutting, and replanting your cannas for the best possible results.

Dividing your cannas is a straightforward task that any gardener can master with just a few basic tools. By taking a little time to refresh your plants, you ensure they have the space and nutrients they need to reach their full potential. The following sections will show you exactly when and how to perform this task so you can enjoy a garden full of tropical color every year.

Why You Should Divide Canna Lily Bulbs

It is helpful to understand how a canna lily grows before you start digging. Although we often call them bulbs, cannas grow from rhizomes. A rhizome is a thick, fleshy underground stem that stores energy for the plant. As the plant grows throughout the summer, the rhizome reaches out horizontally and produces new growth points. Over time, these rhizomes can become very crowded.

Dividing these plants serves three main purposes. First, it helps maintain the health of the plant. When a clump becomes too dense, the individual stems compete for water, nutrients, and sunlight. This competition can lead to smaller leaves and fewer flowers. By dividing the clump, you give each section the room it needs to thrive.

Second, dividing is the most cost-effective way to expand your garden. A single healthy canna plant can often be divided into three or four new plants after just one or two growing seasons. You can use these new starts to fill in other areas of your yard or share them with friends and neighbors.

Finally, dividing is an excellent way to rejuvenate older plants. If you notice that your cannas are producing more foliage than flowers, or if the center of the clump looks a bit sparse, it is likely time to break them up. The fresh energy in the new divisions often leads to a more spectacular floral display in the following season.

The Best Time for Division

The timing of your division depends largely on your local climate and how you manage your garden through the winter. There are two primary windows for dividing canna lily bulbs: the fall and the spring.

Spring Division

For most gardeners, spring is the ideal time to divide cannas. As the soil warms up and the plants begin to wake from their winter dormancy, you will see small, pointed bumps on the rhizomes. These are the "eyes," or growth buds. In the spring, these eyes are often swollen and easy to see, which makes it much easier to decide where to make your cuts.

By dividing in the spring, you can move the new pieces directly into their planting spots or into pots to get an early start. This timing ensures that the cut surfaces of the rhizomes don’t have to sit through a long winter of storage, which reduces the chance of rot. For more timing guidance, see our When Can You Plant Canna Bulbs? guide. (longfield-gardens.com)

Fall Division

If you live in a colder region where cannas must be lifted and stored indoors for the winter, you may find it more convenient to divide them in the fall. Once the first frost has blackened the foliage, you will be digging up the clumps anyway.

Dividing them before storage can save space in your basement or garage. It also allows you to inspect the rhizomes for any signs of damage or disease before you pack them away. If you divide in the fall, just make sure the cut ends have a few days to dry and "cure" before you put them into storage.

Key Takeaway: Spring is the easiest time for beginners because the growth buds are most visible, but fall is a practical choice if you are already lifting the plants for winter storage.

Tools You Will Need

One of the best things about gardening with cannas is that they do not require specialized equipment. You likely already have everything you need in your garden shed. Using the right tools will make the job faster and ensure clean cuts that heal quickly.

• A Sturdy Garden Fork or Spade: A garden fork is often better for lifting the clumps because it is less likely to slice through the rhizomes accidentally. A sharp spade also works well if your soil is very firm.
• A Sharp Knife or Pruners: You will need something to cut the thick rhizomes. A clean, sharp serrated knife (like an old kitchen knife) or a heavy-duty pair of garden pruners is perfect.
• A Garden Hose: Having a source of water nearby helps you wash away the soil so you can see what you are doing.
• Gloves: Canna rhizomes are usually covered in soil, and the sap can be a bit sticky. A pair of sturdy gardening gloves will keep your hands clean and protected.
• Storage Containers: If you are dividing in the fall, have some crates, cardboard boxes, or paper bags ready.

Step 1: Lifting the Clumps

The first step is getting the plants out of the ground without damaging the fleshy rhizomes. If the cannas are still growing, cut the stalks down to about 4 to 6 inches above the soil line. This gives you a "handle" to hold onto while removing the bulk of the foliage that would otherwise get in your way.

Start by digging a circle around the base of the plant. Aim for about 10 to 12 inches away from the main stems. Canna rhizomes grow horizontally, and you want to avoid cutting into the healthy parts of the root system. Insert your garden fork or spade deep into the soil and gently pry upward.

Work your way around the entire clump, loosening the soil as you go. Once the clump feels loose, you can lift it out of the hole. If the clump is very large, don't try to lift it all at once. You can often break off smaller sections while they are still partially in the ground to make them easier to handle.

Lifting from Containers

If you grow your cannas in pots, the process is even simpler. Tip the pot on its side and gently tap the edges to loosen the root ball. You may need to run a long knife around the inside edge of the pot if the plant is root-bound. Slide the entire mass out of the container. In many cases, pot-grown cannas will be so tightly packed that the rhizomes will be visible right against the edges of the soil.

Step 2: Cleaning and Inspection

Once the clump is out of the ground, it will likely be covered in a thick layer of soil. While you can divide them as they are, it is much easier to see the growth buds if you clean them first.

Use your hands to knock off the largest chunks of dirt. Then, use a garden hose to spray the rhizomes with a gentle stream of water. You don’t need to get them perfectly clean, but you want to be able to see the color and texture of the rhizomes.

As you clean, keep an eye out for the following:

• Firmness: Healthy rhizomes should feel firm, similar to a fresh potato.
• Color: Most canna rhizomes are creamy white, light tan, or slightly pinkish on the inside.
• Signs of Rot: If you find any sections that are soft, mushy, or have a foul smell, those parts should be removed and discarded.
• Pests: Look for any holes or signs of tunneling, which could indicate the presence of pests like the canna leaf roller in its larval stage or borers.

Step 3: Identifying the "Eyes"

Before you make any cuts, you need to locate the eyes. An eye is a small, protruding bump or node on the surface of the rhizome. This is where the new stem and leaves will grow from.

A healthy division should have at least two or three of these eyes. While a piece of rhizome with only one eye can grow, it will take much longer to become a full, blooming plant. By ensuring each division has several eyes, you are giving the plant enough stored energy to produce strong growth right away.

In the spring, the eyes often look like small, pointed tips that may even be starting to turn green. In the fall, they may just look like small, raised circular bumps. If you are having trouble finding them, look for where the previous year’s stems were attached; the new eyes are usually located nearby.

What to do next:

• Identify the healthiest, firmest parts of the clump.
• Look for groups of 2–3 eyes that are spaced a few inches apart.
• Plan your cuts so that each piece has a good section of thick rhizome attached to the eyes.

Step 4: How to Divide the Rhizomes

Now it is time to make the divisions. You can often pull the clump apart with your hands, especially if the rhizomes are a bit older and the connections have become brittle. However, using a sharp knife provides a cleaner cut, which heals faster and reduces the risk of disease.

Place the clump on a flat surface or a piece of plywood. Position your knife between the groups of eyes you identified in the previous step. Slice through the rhizome with a firm, steady motion. Try to make the cut as small as possible; a single clean slice is better than several jagged ones.

Each division should be about 3 to 5 inches long. If you have a very large, healthy rhizome, you can cut it into several pieces, provided each one has the necessary eyes. If you come across any old, woody sections of the rhizome that don't have any eyes, you can cut those away and compost them. They have finished their job and won't produce new growth.

Step 5: Curing the Divisions

After you have finished cutting, you will have several "open" wounds on your rhizomes. Just like a cut on your skin, these areas need to heal. This process is called curing.

If you are planting your cannas immediately in a warm climate, you can skip this step, though many gardeners still prefer to let the cuts dry for a few hours. If you are in a cooler climate or plan to store the rhizomes, curing is essential.

Place the new divisions in a shaded, dry area with good air circulation. A garage or a covered porch works well. Let them sit for 24 to 48 hours. During this time, the cut surfaces will dry out and form a "callus" or a tough skin. This callus acts as a barrier, preventing soil-borne bacteria and fungi from entering the rhizome and causing rot.

"A well-cured rhizome is your best defense against rot. Taking just a day or two to let the cuts dry ensures your new plants start their life in the garden strong and healthy."

Step 6: Planting Your New Divisions

When you are ready to plant your newly divided cannas, the most important factor is the soil temperature. Cannas are tropical plants and will not grow until the soil is warm. A good rule of thumb is to wait until the danger of frost has passed and the soil is at least 60°F. This is usually around the same time you would plant tomatoes or peppers.

Choosing the Right Spot

Cannas love the sun. For the most vibrant leaf colors and the best blooms, choose a spot that receives at least 6 to 8 hours of direct sunlight. While they will grow in partial shade, they tend to be taller, floppier, and produce fewer flowers.

They also appreciate rich, well-draining soil. Because they are heavy feeders, it is a great idea to mix in some compost or well-rotted manure before planting. This provides a slow-release source of nutrients that will support their rapid growth through the summer.

Proper Depth and Spacing

Proper planting is the key to a successful start. For a deeper look at planting depth, see How Deep to Plant a Canna Bulb. Follow these simple steps for the best results:

1. Dig a hole: Make it about 4 inches deep.
2. Placement: Lay the rhizome horizontally in the hole. Make sure the eyes are pointing upward.
3. Spacing: Space your divisions about 1 to 2 feet apart. If you want a dense, hedge-like look, stay on the closer end of that range. For individual specimen plants, give them more room.
4. Cover: Fill the hole with soil so the rhizome is covered by about 2 to 3 inches of earth.
5. Water: Give them a good drink to settle the soil around the roots.

Note that cannas can be slow to sprout. Do not be discouraged if you don't see green shoots for a few weeks. As soon as the weather stays consistently warm, they will take off. (longfield-gardens.com)

Dividing Cannas in Containers

If you enjoy growing cannas in pots on your patio or balcony, the division process is very similar, but there are a few extra tips for success. For more container-growing advice, see Can Canna Bulbs Be Planted in Pots?. (longfield-gardens.com)

Container-grown cannas tend to become crowded faster than those in the ground. Because their roots are restricted by the walls of the pot, they can quickly use up the available nutrients. Dividing them every year or two is essential for keeping them looking their best.

When replanting your container divisions, use a high-quality potting mix rather than garden soil. Potting mix is lighter and ensures better drainage, which is vital for preventing rhizome rot. Choose a container that is at least 12 to 18 inches in diameter for a single division. Cannas grow very fast and can easily become top-heavy, so a heavier pot (like ceramic or terracotta) can help prevent the wind from tipping them over.

Make sure your container has drainage holes at the bottom. While cannas love moisture, they do not like to sit in stagnant, soggy water. "Wet feet" can lead to the rhizomes rotting before they ever have a chance to bloom.

Caring for Your New Divisions

Once your divided cannas are back in the soil, they will need a little bit of attention to get established.

Watering

Cannas are thirsty plants. During the heat of the summer, they require consistent moisture. Check the soil frequently; if the top inch feels dry, it is time to water. If you are growing them in pots, you may need to water them every day during the hottest weeks of July and August.

Fertilizing

Because cannas grow so much biomass in a single season, they need plenty of food. We recommend using a balanced, water-soluble fertilizer or a slow-release granular fertilizer every few weeks during the growing season. This will help them produce those giant, lush leaves and continuous flowers.

Deadheading

To keep your cannas looking tidy and to encourage more blooms, practice deadheading. This simply means snipping off the spent flowers before they turn into seed pods. When you see a flower fade, follow the stem down to the next node and make a clean cut. This tells the plant to put its energy into making more flowers rather than producing seeds.

Common Canna Varieties to Divide

At Longfield Gardens, we offer several beautiful varieties that are perfect for dividing. Here are a few favorites that respond exceptionally well to this process:

• Tropicanna: Known for its spectacular multi-colored foliage with stripes of gold, red, and green. It produces vibrant orange flowers and is a true centerpiece in any garden.
• Wyoming: This variety features dark, bronze-purple leaves that provide a stunning contrast to its bright orange blossoms. It is a tall, vigorous grower that is very easy to divide.
• Red King Humbert: A classic choice with dark foliage and deep red flowers. It is incredibly hardy and produces large clumps of rhizomes that are very satisfying to break apart.
• City of Portland: If you prefer softer colors, this variety offers beautiful coral-pink flowers against bright green leaves.

Regardless of the variety you choose, the division process remains the same. The more you divide, the more of these stunning plants you will have to enjoy.

Storing Divisions for the Winter

If you divided your cannas in the fall and live in USDA Zone 6 or colder, you will need to store your divisions until spring. Proper storage is the final step in ensuring your hard work pays off.

Once your divisions have cured for a day or two, wrap each one loosely in a piece of newspaper or place them in a box filled with dry peat moss, vermiculite, or sawdust. This helps regulate the moisture levels and prevents the rhizomes from drying out completely while also discouraging rot.

Store the box in a cool, dark, and dry place where temperatures stay between 40°F and 50°F. An unheated basement or an insulated crawl space is often the perfect spot. Check on your rhizomes once a month during the winter. If they look shriveled, you can lightly mist the packing material with a bit of water. If you see any soft spots starting to form, remove those pieces immediately to prevent the rot from spreading to the rest of the batch.

Summary of the Division Process

Dividing canna lilies is a cyclical part of the gardening year that keeps your landscape looking fresh and vibrant. By following these steps, you can turn one plant into a lush tropical grove over just a few seasons.

Steps for Success:

• Lift: Carefully dig up the clump after the first frost or in early spring.
• Clean: Remove soil and inspect for firm, healthy rhizomes.
• Identify: Locate the eyes (buds) and plan for 2–3 eyes per division.
• Cut: Use a sharp, clean knife to make precise slices.
• Cure: Let the cut ends dry for 24–48 hours to form a protective callus.
• Replant: Place the divisions in warm soil, 4 inches deep, with eyes pointing up.

Conclusion

Dividing canna lily bulbs is one of the most rewarding tasks in the garden. It is a simple, effective way to keep your plants healthy while also providing you with an endless supply of tropical color. By taking the time to lift and separate your rhizomes every few years, you ensure that your summer garden remains a lush and vibrant sanctuary.

• Division prevents overcrowding and encourages more prolific blooming.
• Always ensure each new piece has at least two or three healthy "eyes."
• Patience is key—wait for warm soil before planting your new divisions.
• Healthy rhizomes should feel firm and be free of mushy or dark spots.

We are here to help you succeed every step of the way. For more tips on growing beautiful bulbs and perennials, visit us at Longfield Gardens Learn. For shipping details, see our Shipping Information page, and if you'd like to learn more about the company, visit our About Us page. We wish you a wonderful growing season filled with the bold, beautiful colors of the tropics! (longfield-gardens.com)

"The secret to a stunning canna display isn't complicated tools or expensive fertilizers; it's the simple act of giving the plants the space they need to grow. Division is the gift that keeps on giving to your garden."

FAQ

Can I divide my cannas while they are currently blooming?

It is best to avoid dividing cannas while they are actively blooming. At this stage, the plant is putting all its energy into flower production and foliage. Digging them up and cutting the rhizomes during mid-summer can cause significant stress, which may result in wilting or the loss of flowers. It is much better for the plant's health to wait until they are entering or leaving dormancy in the fall or spring.

How many "eyes" should each division have?

For the best results, each division should have at least two to three healthy eyes. While a single eye can eventually grow into a full plant, a division with multiple eyes has more stored energy and will establish itself much faster. This results in a fuller plant with more stems and flowers in its very first season after being divided.

Do I need to use a special fungicide on the cut ends of the rhizomes?

For most home gardeners, a special fungicide is not necessary. The most important step is to let the rhizomes "cure" or dry in a shaded area for 24 to 48 hours after cutting. This allows the plant to form a natural callus that protects it from rot. However, if you have had issues with rot in the past or live in an exceptionally damp climate, you can lightly dust the cut ends with sulfur powder as an extra precaution.

What should I do if my canna rhizomes look shriveled during winter storage?

If you check your stored divisions and they look dry or shriveled, they need a small amount of moisture. You can use a spray bottle to lightly mist the packing material (like peat moss or newspaper) with water. Do not soak them, as too much water will lead to rot. The goal is to provide just enough humidity to keep the rhizomes firm until it is time to plant them in the spring.