Introduction
There is nothing quite like the moment in midsummer when canna lilies begin to unfurl their massive, tropical leaves. Whether you love the electric orange of a Tropicanna or the classic bronze foliage of "Wyoming," these plants bring a sense of high-energy drama to any landscape. At Longfield Gardens, we enjoy cannas because they are among the most rewarding plants to grow, offering months of color with relatively little effort.
One of the best things about cannas is how quickly they grow and multiply. A single rhizome planted in the spring can become a large, lush clump by autumn. Learning how to split canna lily bulbs—which are technically called rhizomes—is a simple skill that allows you to expand your garden for free and keep your plants looking their absolute best.
This post will guide you through the straightforward process of identifying, cutting, and replanting your cannas for the most successful results. We will cover the best tools for the job, the ideal timing for your region, and how to ensure every new piece thrives. Splitting your cannas is a rewarding way to multiply your garden's beauty and keep your plants vigorous for years to come.
Understanding Canna Rhizomes
Before you pick up your garden tools, it helps to understand what you are looking at. While many gardeners refer to them as bulbs, cannas grow from rhizomes. A rhizome is a thick, fleshy horizontal stem that grows underground. It stores energy and water for the plant, allowing it to produce those tall stems and large flowers.
When you look at a canna rhizome, you will notice it looks somewhat like ginger root. It has segments, and on those segments, you will see small bumps or swollen points. These are the "eyes," and they are the most important part of the division process. Each eye is a potential new stalk.
Dividing these rhizomes is a healthy practice for the plant. If left alone for many years, the center of a large clump can become crowded and woody. This crowding can lead to smaller flowers and less vigorous growth. By dividing them, you give each new section fresh soil and plenty of room to reach its full potential.
Why Splitting Your Cannas is a Great Idea
Cannas are vigorous growers that produce underground stems at a rapid pace. Because these rhizomes grow so quickly, a single plant can become quite crowded in just one or two growing seasons. Dividing your cannas is not just about getting more plants; it is about keeping the plants you already have in top shape.
When a clump of cannas becomes too dense, the plants have to compete for water, nutrients, and space. This can lead to smaller leaves and fewer flowers. By thinning out the clump, you give each new division the room it needs to flourish.
Another benefit of splitting is the ability to refresh your landscape. You can move the new divisions to different parts of your yard or use them to add height and color to large patio containers. It is an easy win for any gardener looking to maximize their summer display without a lot of extra effort.
The Best Time for Division
Timing is a major factor in gardening success. For cannas, the best time to divide the rhizomes depends on where you live and whether you are lifting them for the winter or leaving them in the ground.
Spring Division
In most parts of the United States, spring is the ideal time to divide canna lilies. This usually happens in March or April, just as the plants are beginning to wake up from their winter dormancy. If you stored your rhizomes in a cool, dark place for the winter, you can bring them out and divide them before you start them in pots or plant them in the garden. Dividing in the spring is helpful because the "eyes" are often starting to swell or turn pink, making them very easy to see.
Fall Division
If you live in a colder region where you must lift your cannas to protect them from frost, you can also divide them in the fall. After the first frost has blackened the foliage, you dig up the entire clump. Some gardeners prefer to clean and divide the rhizomes immediately before putting them into winter storage to save space. However, if you do this, you must ensure the cut ends are allowed to "cure" or dry out properly to prevent rot during the winter months.
Key Takeaway: Spring is the easiest time for beginners to divide cannas because the new growth points are clearly visible and the plants are ready to grow immediately as the soil warms.
Tools You Will Need
You do not need specialized equipment to divide cannas, but having the right basic tools will make the process much smoother and safer for the plants.
- A Garden Fork or Spade: Use this to lift the clumps out of the ground without slicing through the middle of the rhizomes.
- A Sharp, Clean Knife: A serrated garden knife or a sturdy kitchen knife works well. It is important that the blade is sharp so you make clean cuts rather than crushing the fleshy tissue.
- Disinfectant: A quick wipe with rubbing alcohol or a 10% bleach solution between different plants helps keep your garden healthy.
- A Garden Hose: This is used to wash away soil so you can clearly see the structure of the rhizome and the location of the eyes.
- Gloves: Canna rhizomes can be muddy, and the sap can sometimes be sticky.
Step 1: Lifting the Clump Safely
If your cannas are currently in the ground, the first step is to get them out safely. Start by cutting back the foliage. If it is fall, cut the stems down to about 4 inches above the soil. If it is spring and you left them in the ground in a warmer zone, do the same.
Use your garden fork to dig a circle around the base of the plant. Stay about 8 to 12 inches away from the outermost stems to avoid hitting the rhizomes. Gently pry upward from several sides to loosen the soil. Cannas can be surprisingly heavy, especially if the soil is damp, so take your time and lift with your legs.
Once the clump is loose, lift it out of the hole and set it on a tarp or a flat patch of grass. If you are growing cannas in containers, simply tip the pot over and slide the root ball out. You may need to tap the sides of the pot to help it release if the plant has become root-bound.
Step 2: Cleaning and Inspecting the Rhizomes
It is very difficult to see where to make your cuts if the rhizomes are covered in dirt. Use a garden hose with a gentle spray to wash away the soil. You do not need to get them perfectly clean, but you want to see the individual "fingers" of the rhizome and the small buds (eyes).
As you clean them, keep an eye out for any sections that feel soft, mushy, or look shriveled. These parts should be discarded. A healthy canna rhizome should feel firm and heavy, much like a fresh potato. Healthy tissue inside will usually appear creamy white or light pink. If you see dark streaks or significant bruising, set those pieces aside to ensure you are only replanting the healthiest material.
Step 3: Identifying the Eyes
This is the most critical part of the process. Look closely at the segments of the rhizome for small, pointed bumps. These may be the same color as the rhizome, or they might be starting to turn white, green, or pink.
Each new division must have at least one healthy eye to grow. For the best results and a fuller plant in the first season, we recommend ensuring each piece has two or three eyes. Pieces without an eye will not produce a plant, as there is no growth point to create a stem. If you have a very large rhizome with many eyes, you can choose to keep it in a larger chunk for a more immediate impact in the garden.
Step 4: Making the Cut
Now it is time to divide. Using your sharp, sanitized knife, cut the rhizomes into smaller sections. Try to find natural "joints" where the rhizome narrows; these are the easiest places to cut and result in the smallest possible wound.
Each section should be roughly 3 to 5 inches long—about the size of a large potato or your fist. If the clump is very large and tangled, do not worry if you have to cut through a thicker section. As long as you use a sharp knife and leave enough eyes on each piece, the plant will be fine. Try to keep the sections roughly the same size so that when you replant them, they grow at a similar rate and create a uniform look in your garden beds.
Step 5: Curing the Divisions
Once you have made your cuts, the rhizomes will have "raw" edges. These need time to heal before they go back into the soil. This process is called curing. Placing a freshly cut rhizome into wet soil can invite bacteria or fungi into the open wound, which may lead to rot.
Place your new divisions in a dry, shaded, well-ventilated area for 24 to 48 hours. A garage, shed, or covered porch works perfectly. This allows the cut surfaces to dry out and form a "callous," which acts as a protective barrier. Once the cut feels dry and corky to the touch, the rhizome is ready to be planted or stored.
What to do next:
- Set the divided pieces on a tray or newspaper in a cool, dry spot.
- Keep them out of direct sunlight during the curing phase.
- Check that the cut ends feel dry and firm before they touch soil.
- Label your varieties immediately so you don't mix up your colors.
Planting Your New Divisions
After the rhizomes have cured, they are ready to go back into the garden or into pots to get a head start. Success at this stage comes down to getting the depth and soil conditions right.
Soil Preparation
Cannas are hungry plants. They love rich soil that stays moist but does not stay soggy. Before planting, we suggest mixing in some compost or well-rotted manure to provide the nutrients they need for fast summer growth. If you have heavy clay soil, adding organic matter will help improve the structure.
Depth and Spacing
Plant your canna rhizomes about 3 to 4 inches deep. The "eyes" should be facing upward, though cannas are resilient enough that they will usually find their way to the surface even if planted sideways. Space the divisions about 1 to 2 feet apart. This might look like a lot of empty space in the spring, but remember that these small pieces will grow into large, bushy plants by July.
For more guidance, see this canna spacing guide.
Light and Water
Cannas need plenty of sunshine to produce their best leaf colors and flowers. A spot with at least 6 to 8 hours of direct sun is ideal. After planting, water them in well to settle the soil around the rhizomes. Once they start growing, keep the soil consistently moist. During the heat of summer, cannas are one of the few garden plants that don't mind extra water, especially if they are growing in containers.
Growing Divided Cannas in Containers
If you don't have much garden space, divided cannas grow beautifully in pots. Using containers also makes it much easier to move the plants around your patio or bring them inside if a late spring frost is predicted.
When planting divisions in pots, choose a container that is at least 12 inches deep and has good drainage holes. Use a high-quality potting mix rather than garden soil, which can be too heavy for pots. A single division with 2–3 eyes is usually enough for a 12-inch pot.
Keep in mind that container plants dry out much faster than those in the ground. During the peak of summer, you may need to water your potted cannas every day to keep the foliage looking lush and prevent the edges of the leaves from turning brown.
For additional advice, read how to grow cannas in pots.
Choosing Varieties for Your Collection
One of the joys of dividing cannas is that you can slowly build a stunning collection and ensure the new plants are identical to the parent. At Longfield Gardens, we offer several varieties that are particularly popular for their reliable performance.
- Tropicanna®: Famous for its multicolored leaves with stripes of purple, green, yellow, and red. It produces bright orange flowers and is a vigorous grower.
- Pretoria: This variety features bold yellow and green striped leaves that look like stained glass when the sun shines through them.
- Wyoming: A classic choice for those who love dark foliage. Its deep bronze-purple leaves provide a perfect contrast to its vibrant orange blooms.
- Red King Humbert: Offers a striking combination of dark bronze foliage and classic red flowers. It is very sturdy and reliable for beginners.
Troubleshooting Common Splitting Concerns
If you have split your cannas and aren't seeing growth after a few weeks, don't worry. There are usually simple explanations. The most common reason for slow growth is soil temperature. Cannas are tropical plants and will sit dormant until the soil is consistently warm (at least 60°F). If you had a chilly spring, they are likely just waiting for the heat.
Another factor could be planting depth. If a rhizome is buried too deep, it will take longer for the sprout to reach the surface. You can gently move a bit of soil aside to check for growth. As long as the rhizome feels firm, it is healthy and will eventually emerge. Finally, ensure you aren't overwatering your new divisions before they have leaves. Without foliage to "breathe" out the moisture, the rhizome can become overwhelmed if the soil stays like a swamp.
For regional timing and winter care, see this canna lily growing zone guide.
Aftercare for Your New Plants
Once your divisions are growing, they need very little specialized care. Because they grow so much leaf mass in a single season, they are heavy feeders. You can apply a balanced, slow-release fertilizer once a month during the growing season to support the foliage and flower production.
To keep your cannas looking tidy and to encourage more flowers, remove the old blossoms once they fade. Simply snip the spent flower stalk off just above the next leaf or bud. This prevents the plant from putting energy into seed production and keeps the focus on the vibrant blooms.
Key Takeaway: Success with cannas is a combination of heat, sun, and water. By providing these three elements, your divided rhizomes will quickly catch up to the size of the original plant.
Conclusion
Mastering the art of how to split canna bulbs is one of the easiest ways to bring more beauty to your home landscape. It is a simple, satisfying process that ensures your plants remain healthy and vibrant year after year. Whether you are filling a large border with the dramatic height of cannas or creating colorful focal points in patio containers, these plants never fail to impress.
- Always identify the "eyes" before making your cuts to ensure growth.
- Allow the cut rhizomes to cure for 24–48 hours to prevent rot.
- Plant in a sunny spot with rich soil once the ground has warmed up.
- Keep your plants well-fed and hydrated for the best summer display.
At Longfield Gardens, we want to help you feel confident in every gardening task. By getting the basics right—like timing, depth, and a clean cut—you can enjoy a spectacular tropical display all summer long. If you are looking to add new colors or textures to your collection, we invite you to explore our selection of Tall Cannas.
"Dividing cannas is like hitting the refresh button on your garden; it gives the plants a boost of energy and gives you twice the flowers for half the effort."
FAQ
When is the best time to split canna lily bulbs?
The best time to divide canna rhizomes is in the early spring, just as they are beginning to wake up from dormancy. If you live in a cold climate and lift your bulbs for the winter, you can also divide them in the fall before putting them into storage, provided you let the cuts dry out first.
How many "eyes" should each division have?
For the best results, each division should have at least two or three "eyes" (growth points). While a piece with only one eye will still grow, having multiple eyes ensures a fuller, more vigorous plant that is likely to produce more stalks and flowers in its first season.
Do I have to let the cut rhizomes dry before planting?
Yes, it is highly recommended to let the cut surfaces "cure" or dry for 24 to 48 hours in a shaded, airy spot. This allows a callous to form, which acts as a protective layer and prevents the rhizome from rotting when it comes into contact with moisture and soil bacteria.
Why didn't my divided canna lilies bloom the first year?
If a division doesn't bloom, it is usually due to a lack of sunlight or nutrients. Cannas need at least 6 to 8 hours of direct sun and rich, fertile soil to produce flowers. Additionally, if the division was very small, it may spend the first year building up its energy stores before it is ready to flower.
For a broader overview of planting, watering, feeding, and winter care, see All About Cannas.
