Table of Contents
- Introduction
- Why Breaking Up Canna Rhizomes Is Important
- Choosing the Right Time to Divide
- Tools for the Job
- Step 1: Lifting the Clump
- Step 2: Identifying Where to Break the Rhizomes
- Step 3: Making the Cut
- Step 4: Curing the Rhizomes
- Storing Your Divisions for Winter
- Replanting Your New Divisions
- Care After Division
- Troubleshooting Common Scenarios
- Enjoying the Results
- Conclusion
- FAQ
Introduction
One of the most rewarding moments in a gardener’s year is realizing that a single, stunning plant has grown into a massive, healthy clump over the summer. Canna lilies are famous for this incredible vigor. Their tropical leaves and vibrant blooms add a sense of drama to the landscape, and the best part is that you can easily turn one plant into several.
At Longfield Gardens, we enjoy seeing how these cannas transform a backyard into a lush oasis. Whether you want to fill a larger flower bed or share some of your favorite varieties with neighbors, learning how to divide them is a simple and satisfying skill. This article will walk you through the process of lifting, cleaning, and breaking up your cannas so you can enjoy more blooms every season.
By following a few straightforward steps, you can keep your plants healthy and expand your garden collection with ease. For a broader overview of planting and care, our All About Cannas guide is a helpful companion.
Why Breaking Up Canna Rhizomes Is Important
While many people call them "bulbs," cannas actually grow from rhizomes, which are thick, fleshy underground stems. These rhizomes act as energy storage tanks for the plant. As the canna grows throughout the summer, the rhizome expands and creates new "eyes" or growth points.
Dividing these rhizomes is more than just a way to get free plants. It is also an essential part of plant maintenance. If a clump stays in the ground for too many years without being broken up, it can become overcrowded. Overcrowded plants often produce smaller leaves and fewer flowers because they are all competing for the same nutrients and space.
Breaking up the clumps every two to three years ensures that each section has plenty of room to develop a strong root system. This practice rejuvenates the plant, leading to the massive, head-turning foliage that cannas are known for. It is a simple way to maintain the high-quality performance you expect from your garden.
Choosing the Right Time to Divide
Timing is one of the most important factors when it comes to successfully breaking up cannas. The two primary windows for this task are late autumn and early spring. If you want a quick reference for your climate, check the Hardiness Zone Map. The right choice for you often depends on your local climate and how you plan to overwinter your plants.
Autumn Division (Before Storage)
In colder regions (USDA zones 6 and lower), canna rhizomes must be lifted and stored indoors for the winter. Many gardeners find it easiest to break the clumps apart right after the first frost has blackened the foliage. Dividing in the fall saves storage space and allows you to inspect the health of the rhizomes before they go into dormancy.
Spring Division (Before Replanting)
If you live in a warmer climate (zones 7 to 10) where cannas can stay in the ground, or if you prefer to store your clumps whole, spring is the ideal time to divide. For more help matching plants to your region, read our Know Your Growing Zone: Cold Hardiness and Heat Tolerance guide. As the soil begins to warm and you see the first hints of new growth, you can lift the clumps and break them into smaller sections for replanting. This is also a great time to start them in pots if you want an early start on the season.
Key Takeaway: Choose autumn division if you have limited storage space, or spring division if you want to see exactly where the new growth is starting before you make your cuts.
Tools for the Job
You do not need a shed full of specialized equipment to divide cannas. In fact, most of what you need is likely already in your garden kit. Having the right tools ready will make the process faster and help prevent damage to the fleshy rhizomes.
- A Sturdy Garden Fork or Shovel: A garden fork is often preferred because it is less likely to slice through the rhizomes accidentally. If you use a shovel, be sure to give the clump plenty of space.
- A Sharp, Clean Knife: A simple serrated garden knife or a sharp kitchen knife works well. It is important that the blade is clean to prevent the spread of soil-borne issues.
- A Garden Hose: A quick spray of water is the easiest way to remove soil so you can see what you are doing.
- Gloves: Canna rhizomes can be muddy, and a good pair of gardening gloves will protect your hands while you work.
Step 1: Lifting the Clump
The process begins with getting the rhizomes out of the ground safely. Because canna rhizomes grow horizontally and can spread quite wide, you want to avoid digging too close to the main stems.
Start by cutting the foliage back to about 4 to 6 inches above the soil line. This makes the clump much easier to handle. Next, insert your garden fork or shovel into the soil about a foot away from the base of the plant. Gently rock the tool back and forth to loosen the earth. Work your way around the entire perimeter of the plant until the clump feels loose.
Slowly lift the clump from underneath. If the plant is several years old, the root ball might be heavy, so take your time. Once the clump is on the surface, shake off the excess loose soil.
Cleaning for Clarity
It can be difficult to see where to make your cuts if the rhizomes are covered in mud. Use a garden hose with a gentle spray to wash away the remaining dirt. Once the rhizome is clean, you will clearly see the "eyes"—small, pointed bumps that look like the eyes on a potato. These are the points where next year's stems will emerge.
Step 2: Identifying Where to Break the Rhizomes
Before you reach for your knife, take a moment to inspect the clump. A healthy canna rhizome should feel firm and heavy. If you find any soft, mushy, or shriveled areas, those can be trimmed away and discarded.
The goal is to break the large clump into smaller sections that each have a good chance of thriving. Each new division needs at least two or three healthy eyes and a portion of the fleshy rhizome attached to provide energy.
Look for natural "nodes" or narrow points in the rhizome. These are the easiest places to snap or cut the plant. If the clump is very large, you might be able to pull it apart with your hands. If it is tightly packed, a clean cut with a knife is the better option.
What to Do Next:
- Identify the "eyes" (the small growing points).
- Locate the natural narrow joints between rhizome sections.
- Ensure each section you plan to cut has at least 2–3 eyes.
- Check that the section feels firm and healthy before cutting.
Step 3: Making the Cut
Once you have identified your planned divisions, it is time to separate them. If you are using a knife, make a clean, swift cut through the narrowest part of the rhizome. A clean cut heals faster than a jagged or torn edge.
If a piece accidentally breaks off and only has one eye, don't worry. It will likely still grow, though it may take a little longer to reach its full height compared to a larger division. The most important thing is that each piece has a healthy section of the "body" to fuel its initial growth.
After you have finished breaking up the clump, you will likely have several new plants ready to go. This is a great time to label your divisions if you are working with multiple varieties like 'Tropicanna' or 'Wyoming,' as the rhizomes all look very similar once the leaves are gone.
Step 4: Curing the Rhizomes
"Curing" is a simple but vital step, especially if you are dividing in the fall for winter storage. When you cut a rhizome, you create a "wet" wound. If you immediately pack that wet rhizome into a storage box or plant it in cold, damp soil, it is more susceptible to rot.
To cure your cannas, lay the divided pieces out in a dry, shaded area for 2 to 3 days. This allows the cut surfaces to dry out and form a "callus" or tough skin. Think of it like a scab that protects the plant. Once the cuts feel dry and firm to the touch, they are ready for the next stage of their journey.
Storing Your Divisions for Winter
If you have divided your cannas in the fall, they need a cozy place to rest until spring. Proper storage is the key to ensuring they wake up ready to grow.
We recommend using a breathable container, such as a cardboard box or a plastic bin with air holes. Fill the container with a slightly damp (but not wet) medium like peat moss, perlite, or even shredded newspaper. Place the rhizomes in the box so they are not touching each other. This prevents any issues from spreading from one piece to another.
Store the box in a cool, dark place where temperatures stay between 40°F and 50°F. An unheated basement, a crawl space, or a cool closet usually works perfectly. Check on them once or twice during the winter; if the rhizomes look shriveled, a light misting of water will help them stay hydrated.
Replanting Your New Divisions
When spring arrives and the danger of frost has passed, it is time to bring your cannas back into the garden. Wait until the soil temperature has reached at least 60°F—usually about the same time you would plant tomatoes.
In the Ground
Choose a spot with full sun and well-draining soil. Dig a hole about 4 inches deep and place the rhizome horizontally with the eyes facing upward. If you aren't sure which way is up, don't worry; the plant will figure it out. Space your new divisions about 1 to 2 feet apart to give them room to grow into large, beautiful clumps again.
In Containers
Cannas are fantastic container plants. Use a high-quality potting mix and a pot that is at least 12 to 18 inches wide. Planting in containers is a great way to add height to a patio or balcony. Because pots warm up faster than the ground, container-grown cannas often start blooming earlier in the season. For more container-growing ideas, see our Best Summer Bulbs for Containers.
Key Takeaway: Always wait for warm soil before planting. Cannas love heat, and they will grow much faster if you wait for the right conditions rather than rushing them into cold ground.
Care After Division
Dividing can be a bit of a workout for a plant, but cannas are incredibly resilient. Once they are replanted, they will need a little extra attention to help them get established.
- Watering: Water your new divisions well immediately after planting. Keep the soil consistently moist. Cannas are "thirsty" plants and will reward regular watering with lush, oversized leaves.
- Fertilizing: These plants are heavy feeders. Once you see a few inches of green growth, you can begin applying a balanced liquid fertilizer or a slow-release granular option. This provides the energy they need to produce those tall, striking flower spikes.
- Mulching: A thin layer of mulch around the base of the plants helps retain moisture and keeps the soil temperature stable.
Troubleshooting Common Scenarios
While breaking up canna bulbs is usually straightforward, you might encounter a few unique situations. Here is how to handle them with ease.
What if the rhizome is too hard to cut?
Older clumps can sometimes become very woody and tough in the center. If your garden knife isn't doing the trick, you can use a clean pair of loppers or even a small hand saw. As long as the cut is relatively clean, the plant will be fine.
What if I see small holes in the rhizome?
If you notice any tunneling or small holes, this might be a sign of a garden pest. Simply trim away the affected area until you reach clean, white flesh. It is better to have a slightly smaller, healthy division than a large one with issues.
What if I forgot to divide in the fall?
If you missed the autumn window, don't worry! You can easily divide them in the spring. In fact, many gardeners prefer spring division because the eyes are starting to swell and turn pink or green, making them much easier to see.
Enjoying the Results
The best part of breaking up canna bulbs is the transformation that happens over the next few months. By mid-summer, the small pieces you cut will have grown into tall, majestic plants. You’ll have more color in your garden, more flowers for local pollinators, and more foliage to create that tropical getaway feeling right at home. Maybe this year you’ll try a row of Pretoria along a fence.
Or a group of Stuttgart in a shady corner to show off their variegated leaves.
What to Do Next:
- Check your soil temperature with a simple thermometer.
- Prepare your planting holes with a bit of compost.
- Plant your callused divisions 4 inches deep.
- Keep the soil moist and wait for the first green shoots to appear.
Conclusion
Dividing cannas is one of the most practical and rewarding tasks in the garden. It takes a little bit of effort to lift and cut the clumps, but the payoff is a healthier, more beautiful landscape. By following these simple steps—lifting carefully, identifying the eyes, making clean cuts, and allowing the rhizomes to cure—you can ensure your cannas return better than ever each year.
At Longfield Gardens, we believe that gardening should be a source of joy and discovery. If you'd like more creative planting inspiration, browse our Fresh Ideas for Growing Cannas. We hope this guide gives you the confidence to get out there and start expanding your tropical paradise.
- Divide in spring or fall depending on your climate and storage needs.
- Ensure each piece has 2-3 eyes for the most vigorous growth.
- Cure the cuts for a few days to prevent rot before planting or storing.
- Plant in warm soil (60°F) to get the best start for the season.
Ready to add more color to your yard? Explore our Tall Cannas and start planning your most vibrant garden yet.
FAQ
How many times can I divide a single canna clump?
You can divide a clump as many times as there are healthy sections with at least two or three eyes. For a large, established plant, it is common to get five to ten new divisions from a single root ball.
Do I have to use a knife to break them apart?
Not necessarily. If the rhizome clump is loose, you can often pull it apart with your hands or gently pry it with a garden fork. However, using a sharp knife provides a cleaner wound that typically heals faster and reduces the risk of unintended damage.
What happens if I plant a division that doesn't have any eyes?
If a piece of rhizome has no eyes, it generally will not be able to produce new stems. The eyes are the dormant buds where growth begins. Always make sure each piece has at least one visible "bump" or node before planting.
Can I leave my cannas in the ground instead of lifting and dividing?
In USDA zones 7 to 10, cannas can stay in the ground all year. However, even in these warm areas, it is still a good idea to lift and divide them every three years. This prevents the clump from becoming too dense, which can lead to fewer flowers and smaller leaves.
Explore our Canna Assorted Mix - Bulk Offer and start planning your most vibrant garden yet.