Introduction
There is nothing quite like the sight of a canna lily in full glory, with its towering, banana-like leaves and brilliant tropical blooms. These plants are the heavy hitters of the summer garden, providing a lush backdrop that makes any backyard feel like a private island retreat. If your cannas have performed well, you might notice that the clumps are getting larger each year. This leads many gardeners to wonder: can you split canna lily bulbs to get even more of that vibrant color?
The answer is a resounding yes. Splitting, or dividing, canna lilies is one of the most rewarding tasks in the garden. At Longfield Gardens, we love helping gardeners realize that their favorite plants are often the "gift that keeps on giving." By learning a few simple techniques for dividing these hardy growers, you can expand your flower beds or share the beauty with friends and neighbors. For a ready-made mix, try our Canna Assorted Collection.
In this guide, we will walk through the straightforward process of splitting canna lily rhizomes, explaining when to do it and how to ensure your new divisions thrive. Whether you are looking to tidy up an overgrown patch or want to double your display for next summer, splitting your cannas is an easy win for any skill level.
What Are Canna Lily Bulbs?
Before we dive into the "how," it helps to understand what we are actually working with. While most people call them "bulbs," canna lilies actually grow from rhizomes. A rhizome is a thick, fleshy horizontal stem that grows just beneath the soil surface. Unlike a true bulb (like a tulip), which is a complete self-contained plant in a tiny package, a rhizome acts more like a continuous energy storage system that creeps along and sends up new shoots as it moves.
Understanding this growth habit is key to successful splitting. As the rhizome grows, it develops "eyes." These eyes are small, often pinkish or white bumps that serve as the growth points for next year’s stems and leaves. When we talk about splitting canna lily bulbs, we are essentially cutting these thick rhizomes into smaller pieces, ensuring each piece has enough stored energy and at least one healthy eye to start a new plant.
Why You Should Split Your Canna Lilies
You might be tempted to let your canna lilies grow into one massive, impressive colony. While they look great for a few years, eventually, even the hardiest cannas will benefit from a little intervention. Dividing your plants is not just about getting more flowers for free; it is a vital part of plant health.
Preventing Overcrowding
Cannas are vigorous growers. Over time, the rhizomes can become so tightly packed that they begin to compete with one another for water, nutrients, and space. When a clump becomes too dense, you may notice that the stems are thinner and the flowers are smaller or less frequent. Splitting the clump gives each plant the room it needs to reach its full potential.
Revitalizing Older Plants
In the center of a very old canna clump, the rhizomes can sometimes become woody or spent. By lifting and splitting the clump, you can discard those older, less productive pieces and focus your garden’s energy on the younger, more vigorous sections. This keeps your garden looking fresh and prevents the "dead center" look that sometimes happens with perennials.
Easy Propagation
The most exciting reason to split cannas is propagation. If you started with a single 'Orange Punch' or 'Tropical Bronze' canna, you might find that after a few seasons, you have enough rhizomes to fill three or four large containers or an entire garden border. It is a cost-effective way to create a high-impact, cohesive look throughout your landscape.
Key Takeaway: Dividing canna lilies every two to three years prevents overcrowding, improves flowering, and provides you with a supply of new plants to expand your garden.
When Is the Best Time to Split?
Timing is everything in gardening, but cannas are quite flexible. There are two primary windows for splitting your canna lily rhizomes: in the fall during the "lifting" process, or in the spring before you replant them. If you want a quick primer on timing and regional conditions, see our hardiness zone map.
Splitting in the Fall
If you live in a region where the ground freezes (USDA zones 6 and colder), you will likely be digging up your cannas to store them for the winter. This is an excellent time to split them. Once you have lifted the clump and shaken off the excess soil, the structure of the rhizomes is very easy to see. Splitting them now makes them easier to store in smaller, manageable containers or bags.
Splitting in the Spring
Many gardeners prefer to wait until spring to do their dividing. After a winter of storage, the "eyes" on the rhizomes often become more prominent and easier to identify. Splitting in the spring, about four to six weeks before your last frost date, allows you to see exactly which parts of the rhizome are the healthiest and ready to grow. If you live in a warm climate (Zones 8-11) where cannas stay in the ground year-round, early spring is the ideal time to dig and divide them just as new growth begins to emerge. For more detail on matching plants to your climate, read Know Your Growing Zone: Cold Hardiness and Heat Tolerance.
Tools You Will Need
You do not need an arsenal of specialized equipment to split canna lilies. In fact, keeping it simple is usually best. Here are the basic tools we recommend having on hand:
- A sturdy garden fork or spade: Used for lifting the entire clump out of the ground without slicing through the rhizomes.
- A garden hose: Helpful for washing away soil so you can clearly see the "eyes" and the joints of the rhizomes.
- A sharp, clean knife: A simple serrated kitchen knife or a dedicated garden knife works well for making clean cuts.
- Rubbing alcohol: To disinfect your knife between plants to prevent the spread of any potential soil-borne diseases.
- Gloves: Canna rhizomes are generally easy to handle, but gloves keep your hands clean and protect against accidental nicks.
Step 1: Lifting the Canna Clump
The process begins with getting the plants out of the soil. If you are doing this in the fall, wait until after the first light frost has blackened the foliage. This signal tells the plant to move its energy down into the rhizome for winter storage.
Start by cutting the stems back to about 3 to 4 inches above the soil line. Using your garden fork, begin digging a circle around the clump. Canna rhizomes can spread surprisingly far, so start digging about 12 inches away from the main stems to avoid accidentally stabbing the fleshy roots.
Gently pry upward from several sides to loosen the soil. Once the clump is loose, lift it out. Don't worry if it feels heavy; a healthy canna clump can be quite substantial!
Step 2: Cleaning the Rhizomes
It is much easier to see where to make your cuts if the rhizomes are clean. Use your hands to knock off large chunks of soil. If the soil is heavy clay and sticking to the roots, use a garden hose to gently wash the clump.
Once the soil is gone, you will see a network of thick, ginger-like roots. Look for the "eyes"—these are the small, pointed bumps. Each division you make must have at least one of these eyes to successfully grow into a new plant next season. Most experts suggest aiming for two or three eyes per piece to ensure a strong, bushy plant in the first year.
Step 3: Making the Split
Now comes the part that often makes beginners nervous, but we promise it is easy. Examine the clump to find natural "weak points" where the rhizomes branch off from one another.
- Identify your pieces: Look for sections that are about 3 to 5 inches long with several healthy eyes.
- Make the cut: Using your clean knife, slice through the rhizome. You want a clean, straight cut rather than a jagged one. Some rhizomes may even snap apart naturally with a little pressure from your hands.
- Discard the old bits: If you find any parts of the rhizome that feel soft, hollow, or look shriveled and woody, toss them in the compost. You only want to keep the firm, healthy-looking sections.
- Sanitize: Wipe your knife with rubbing alcohol after working on one clump before moving to the next. This simple step is a great habit for keeping your garden healthy.
What to do next:
- Count your new divisions so you can plan your garden layout.
- Check each piece for firmness; healthy rhizomes should feel like a fresh potato.
- If splitting in the fall, let the cut ends dry for a day or two before storing.
Step 4: The "Curing" Process
If you split your cannas in the fall or even in the late spring, it is helpful to let the cut ends "cure" before they go into storage or back into the ground. Curing simply means letting the cut surface dry out and form a callous.
This callous acts as a protective barrier that prevents rot-causing bacteria and fungi from entering the fleshy rhizome. Place your divisions in a dry, shaded area with good air circulation for 24 to 48 hours. Once the cut ends feel dry and firm to the touch, they are ready for their next step.
Storing Your New Divisions (Fall Method)
If you have divided your cannas in the fall, you now have a collection of healthy rhizomes that need to sleep through the winter. Proper storage is the secret to a successful spring start.
We recommend storing your divisions in a breathable container, such as a cardboard box, a plastic bin with air holes, or a paper bag. To keep them from drying out completely, nestle them in a moisture-wicking material like peat moss, vermiculite, or even slightly damp sawdust.
Store the container in a cool, dark place where temperatures stay between 40°F and 50°F. A basement, crawlspace, or insulated garage is usually perfect. Check on them once or twice during the winter; if they look shriveled, a very light misting of water will help, but be careful not to make them soggy. For more seasonal guidance, see our shipping information.
Planting Your New Divisions (Spring Method)
Whether you just divided your rhizomes or took them out of winter storage, planting is where the fun begins. Cannas are heat-lovers, so there is no rush to get them in the ground while the soil is still chilly.
Site Selection
Cannas thrive in full sun—the more, the better! They need at least 6 to 8 hours of direct light to produce those signature bold colors. They also love moisture, so a spot that stays slightly damp but has good drainage is ideal. If your soil is very sandy, adding some compost will help hold the moisture they crave.
Planting Depth and Spacing
Getting the depth right is one of those "quiet wins" in gardening. Dig a hole about 4 inches deep. Place the rhizome horizontally in the hole with the eyes facing upward.
Space your divisions about 1 to 2 feet apart. While they look small now, remember that varieties like Stuttgart or Tropicanna can grow quite large and will fill that space quickly. Cover the rhizome with soil and firm it down gently with your hands to remove air pockets.
Watering and Initial Care
Water the area thoroughly right after planting to settle the soil. After that initial watering, be patient. Cannas are slow to wake up, and if the soil is too wet and cold before they start growing, the rhizomes can rot. Wait until you see the first green shoots poking through the soil before you begin a regular watering schedule.
Growing Cannas in Containers
If you have split your cannas and find yourself with more plants than garden space, containers are a perfect solution. A single division in a 12-inch or 15-inch pot creates a stunning vertical accent for a patio or porch.
When planting in pots, use a high-quality potting mix that drains well. Containers dry out faster than the ground, so you will likely need to water your potted cannas more frequently during the heat of the summer. A slow-release fertilizer added at planting time will give them the "fuel" they need to produce those massive leaves and blooms in a confined space. A Canna Tall Tropicanna Black can make a dramatic container specimen.
Simple Troubleshooting After Splitting
Occasionally, a gardener might find that a division isn't sprouting as quickly as expected. Before you worry, remember that cannas are tropical plants—they are waiting for the "alarm clock" of warm soil.
- Wait for Warmth: If the soil temperature is below 60°F, the canna will stay dormant. Once the summer heat arrives, they usually take off rapidly.
- Check Depth: If you planted them much deeper than 4 or 5 inches, they might just need a little more time to reach the surface.
- Firmness Test: If you are truly concerned, you can gently brush away a little soil to feel the rhizome. If it is still firm, it is healthy and just taking its time. If it feels mushy, it may have rotted due to overwatering in cold soil.
"The most important ingredient for canna lily success isn't a special fertilizer or a secret trick—it is simply the patience to wait for the summer sun to do its work."
Caring for Your Cannas Through the Season
Once your new divisions are established, they are remarkably low-maintenance. To keep them looking their best, follow these simple tips:
- Watering: Keep the soil consistently moist. If the leaves start to roll up like a cigar, it is a sign the plant is thirsty.
- Feeding: Cannas are "hungry" plants. A balanced garden fertilizer applied once a month during the growing season will reward you with taller stems and more flowers.
- Deadheading: When a flower cluster fades, snip it off. This prevents the plant from putting energy into seed production and encourages it to send up new flower spikes.
- Foliage Care: You can leave the foliage alone until the end of the season. The leaves are busy capturing sunlight to recharge the rhizome for next year.
At Longfield Gardens, we have seen how a single canna rhizome can transform a garden over just a few years. By splitting your cannas, you are not just maintaining a plant; you are participating in the natural cycle of growth and renewal that makes gardening so satisfying. For more inspiration, browse our cannas blog category.
Conclusion
Splitting canna lily bulbs—or rhizomes—is a simple, rewarding task that ensures your garden remains vibrant and healthy year after year. By following the natural cues of the seasons and using a sharp knife to create new divisions, you can easily double or triple your tropical display. Remember to look for the "eyes," give your cuts time to callous, and wait for the warm summer soil before expecting rapid growth.
- Divide every 2–3 years to prevent overcrowding.
- Ensure each division has at least 1–3 healthy eyes.
- Plant in full sun and keep the soil moist for the best blooms.
We are proud to provide high-quality rhizomes and the practical advice you need to succeed. Whether you are planting your very first canna or dividing a long-loved heirloom clump, we are here to support your journey toward a more beautiful landscape.
FAQ
Can I split canna lilies while they are blooming?
While it is physically possible, it is not recommended. Splitting a plant while it is in full bloom or active growth causes significant stress, which can lead to wilting and a loss of flowers. It is much better for the plant’s health to wait until it is dormant in the late fall or early spring.
Do I have to use a knife to split canna rhizomes?
You don't always need a knife; sometimes the rhizomes are brittle enough to be snapped apart by hand at the natural joints. However, using a sharp, clean knife creates a smoother surface that heals faster and reduces the risk of tearing the fleshy tissue, which helps prevent rot.
What happens if I plant a division that doesn't have an "eye"?
If a piece of rhizome does not have a visible eye or growth node, it likely will not grow. The rhizome contains the energy, but the eye contains the genetic instructions and "starting point" for the new stem. Always ensure each piece has at least one firm, healthy bump before planting.
Should I soak canna rhizomes in water before planting?
Some gardeners like to soak their rhizomes for 12 to 24 hours to "wake them up," especially if they look very dry after winter storage. While not strictly necessary, a brief soak can help jumpstart the hydration process, but be sure to plant them immediately after soaking so they don't sit in stagnant water. For more on that, see Do You Soak Canna Lily Bulbs Before Planting?
