Table of Contents
- Introduction
- Understanding the Canna Rhizome
- The Best Time for Splitting Canna Bulbs
- Preparing Your Cannas for Division
- Step-by-Step Guide to Splitting Rhizomes
- Planting Your New Canna Divisions
- Growing Cannas in Containers
- Spotlight on Favorite Canna Varieties
- Long-Term Care After Dividing
- Realistic Expectations for Your Divisions
- Conclusion
- FAQ
Introduction
There is nothing quite like the tropical flair that cannas bring to a summer garden. Their oversized, banana-like leaves and vibrant blossoms create an instant vacation vibe in any backyard or patio. If you have grown these stunning plants before, you know how quickly they can expand and fill a space.
At Longfield Gardens, we believe that every gardener should enjoy the satisfaction of a lush, thriving landscape. One of the easiest ways to multiply your garden’s beauty is by learning the simple process of splitting canna bulbs. This practice, technically known as dividing rhizomes, helps keep your plants healthy and provides you with plenty of new starts to share or plant elsewhere.
This guide will walk you through the timing and techniques for dividing your cannas successfully. For a broader overview of planting and care, see All About Cannas. Whether you are a beginner or a seasoned gardener, you will find that this straightforward task is a rewarding way to get the most out of your plants. Splitting canna bulbs is the best method for refreshing older clumps and ensuring a spectacular display of color every single year.
Understanding the Canna Rhizome
Before you pick up your garden tools, it is helpful to understand what you are working with. While many people refer to them as "bulbs," cannas actually grow from rhizomes. A rhizome is a thick, fleshy underground stem that grows horizontally. It stores energy for the plant and sends out both roots and new shoots as it spreads.
Over a single growing season, a small rhizome can triple or even quadruple in size. This rapid growth is why cannas are so popular for creating quick privacy screens or filling large containers. However, this same vigor means the plants can eventually become crowded. When the rhizomes are packed too tightly together, they may produce fewer flowers and smaller leaves.
Splitting these rhizomes solves the problem of overcrowding. It also allows you to inspect the health of your plants. A healthy canna rhizome should feel firm and heavy for its size. By dividing them, you are essentially "resetting" the plant, giving each new section its own space to draw nutrients and water from the soil.
The Best Time for Splitting Canna Bulbs
Timing is everything when it comes to garden success. For most gardeners in the United States, the ideal time to split canna bulbs is in the spring. This is the moment when the plants are just waking up from their winter dormancy and are ready to start a new cycle of growth.
If you live in a warm climate (Zones 8 to 11), your cannas may stay in the ground all year. In these regions, you can dig and divide them in late winter or early spring before they send up significant new foliage. For gardeners in cooler climates (Zones 3 to 7), cannas are typically dug up in the fall and stored indoors for the winter. If you are not sure which zone you live in, check the Hardiness Zone Map. In this case, the best time to divide them is in the spring, just before you are ready to start them into growth.
Watching for "eyes" is the most reliable way to time your division. The eyes are the small, swollen bumps or reddish points on the rhizome. These are the growth buds where new stems will emerge. When these eyes begin to swell and look slightly plump, the plant is ready to be divided and replanted.
Key Takeaway: Always wait until the danger of frost has passed if you are planting directly into the ground, or start your divisions indoors 4 to 6 weeks before the last frost date for an early head start on the season.
Preparing Your Cannas for Division
If your cannas have been overwintering in a cool, dark place like a basement or garage, bring them out into a warmer area to wake them up. You may want to lightly mist the storage medium with water to signal that it is time to grow. If you are digging them directly from the garden, start by clearing away any mulch or debris from the base of the plant.
Use a garden fork rather than a spade if possible. A fork is less likely to slice through the middle of a healthy rhizome. Gently lift the entire clump out of the soil. Once the clump is out, shake off the excess dirt so you can clearly see the structure of the rhizomes. If the soil is particularly sticky or heavy, you can use a garden hose to gently wash the rhizomes clean.
Seeing the "nodes" and "eyes" is much easier when the rhizomes are clean. This clarity helps you make smarter cuts and ensures each piece you create has the potential to become a full, blooming plant. For more detailed storage help, see How to Dry Out Canna Bulbs for Winter Storage.
What to Look For:
- Firmness: Avoid any sections that feel soft, mushy, or hollow.
- Color: Healthy rhizomes are typically creamy white, tan, or pinkish on the inside.
- Growth Buds: Look for at least one to three prominent "eyes" on every section you plan to keep.
Step-by-Step Guide to Splitting Rhizomes
Splitting cannas is a very forgiving process. These plants are tough and resilient, so you do not need to worry about being overly delicate. As long as you follow a few basic steps, your new divisions will likely take off and thrive.
Step 1: Identify Your Cut Points
Look at the large clump and identify the natural "elbows" or narrow points where the rhizomes connect. These narrow areas are the best places to make your cuts. Ensure that each section you plan to cut away has at least two healthy-looking eyes. While a single eye can grow into a plant, having two or three eyes per piece will result in a fuller, more robust plant in the first season.
Step 2: Make Clean Cuts
Use a sharp, clean garden knife or a pair of bypass pruners. It is a good idea to wipe your blade with rubbing alcohol between different plants to prevent the spread of any potential soil-borne issues. Slice firmly through the rhizome at your identified cut point. Try to make the cut as clean as possible rather than jagged.
Step 3: Size the Divisions
A good rule of thumb is to aim for pieces that are roughly 3 to 5 inches long. If a rhizome is exceptionally large and has many eyes, you can leave it as a larger chunk, but dividing it into smaller pieces actually encourages more vigorous new growth. It also gives you more individual plants to place around your garden.
Step 4: Let the Cuts Callus
This is a small but important step that many gardeners skip. After you have made your cuts, the "wounds" on the rhizome are wet and exposed. Leave the divided pieces in a warm, dry, shaded spot for 12 to 24 hours. This allows the cut surfaces to dry out and form a "callus," which acts as a protective barrier against soil moisture.
Key Takeaway: A sharp knife and a bit of patience during the callusing phase are the two simplest ways to ensure your new canna starts get off to a healthy beginning.
Planting Your New Canna Divisions
Once your canna pieces have callused over, they are ready for their new homes. Cannas are not particularly picky, but they do have a few preferences that will help them reach their full potential. We maintain trial gardens to evaluate how different varieties perform, and our About Us & Our Guarantee page explains the standards behind every order.
Soil and Sunlight
Cannas are sun-lovers. They need at least 6 to 8 hours of direct sunlight every day to produce those iconic, colorful flowers. If they are planted in too much shade, the plants will become "leggy," stretching for the light, and they may never bloom.
The soil should be rich and well-draining. While cannas love moisture, they do not like to sit in stagnant water. If you have heavy clay soil, adding some compost or aged manure will help improve the drainage and provide the nutrients these hungry plants crave.
Planting Depth and Spacing
The quiet winners of a successful garden are often correct depth and spacing. For canna rhizomes, follow these simple rules:
- Depth: Plant the rhizomes 3 to 4 inches deep.
- Orientation: Lay the rhizome horizontally in the hole. If you can see the eyes, point them upward, but do not worry too much—the plant will find its way to the surface either way.
- Spacing: Give them room to grow. Space standard varieties about 18 to 24 inches apart. For dwarf varieties, 12 inches is usually sufficient.
Watering and Initial Care
After planting, water the area thoroughly to settle the soil around the rhizomes. After that initial watering, be patient. If the soil is cool and damp, you do not need to water again until you see the first green sprouts poking through the ground. Overwatering before the plant has roots and leaves to use that water can lead to issues. Once the plants are established and the weather warms up, cannas will appreciate regular, deep watering.
Growing Cannas in Containers
If you do not have a large garden bed, you can still enjoy divided cannas in pots. In fact, cannas are some of the best plants for large containers because they provide height and drama. If you are shopping for a medium-sized variety, the Medium Cannas collection offers a good fit.
When planting your divisions in a pot, choose a container that is at least 12 to 15 inches in diameter. If you want a step-by-step container planting guide, see How to Plant Canna Lily Bulbs in Pots. Use a high-quality potting mix that drains well. Because containers dry out faster than the ground, you will need to water your potted cannas more frequently, especially during the heat of mid-summer.
Splitting cannas that have been growing in pots is especially important. Because the roots are confined, the rhizomes can quickly fill the entire container, leading to a "root-bound" plant that struggles to stay hydrated. Dividing your potted cannas every spring ensures they have fresh soil and plenty of room to expand.
Spotlight on Favorite Canna Varieties
When you split your canna bulbs, you are often preserving a specific variety that you love. There are hundreds of types to choose from, but a few stand out for their exceptional performance and beauty. For more ideas, browse our Tall Cannas collection.
Foliage-Focused Varieties
- Pretoria (Bengal Tiger): This is one of the most striking cannas available. It features bright green leaves with vivid yellow stripes and glowing orange flowers. Even when it isn't blooming, the foliage is a showstopper.
- Tropicanna: Known for its multi-colored leaves featuring shades of burgundy, gold, pink, and green. It creates an instant tropical focal point.
- Wyoming: This variety offers dark, bronze-purple foliage that provides a wonderful contrast to the bright orange, ruffled flowers.
Classic Flower-Focused Varieties
- Red King Humbert: A tall, stately variety with bronze leaves and classic, deep red flowers. It is a hummingbird favorite.
- City of Portland: A beautiful choice for those who love softer colors. It produces large, coral-pink blossoms over lush green foliage.
- Lucifer: A popular dwarf variety that stays compact (about 2-3 feet tall). It features bright red flowers with a distinct yellow border, making it perfect for the front of a border or small containers.
Long-Term Care After Dividing
Once your divided cannas are growing, they are relatively low-maintenance. However, a little extra attention during the peak of the season will keep them looking their best. For more inspiration on using cannas in beds and containers, see Fresh Ideas for Growing Cannas.
Fertilizing
Cannas are "heavy feeders." They grow a massive amount of foliage and large flowers in a very short amount of time. To support this growth, you can apply a balanced, slow-release fertilizer in early summer. If you prefer liquid fertilizer, applying it every few weeks during the growing season will help maintain those vibrant colors.
Deadheading
To keep the flowers coming, practice "deadheading." This simply means cutting off the spent flower stalks once they have finished blooming. Cut the stalk back to the next side bud or where it emerges from the foliage. This prevents the plant from putting energy into seed production and encourages it to produce more blooms.
Support for Tall Varieties
Some of the taller canna varieties can reach heights of 6 to 8 feet. In windy areas, these tall stems may benefit from staking. Use a simple bamboo stake and soft garden twine to give them a little extra stability during summer storms.
Realistic Expectations for Your Divisions
When you split a canna rhizome, it is important to remember that the first year is a time of transition. While most divisions will bloom in their first season, the plant might be slightly smaller than a fully established clump. This is perfectly normal. The plant is busy building a new root system and establishing itself in its new home.
The weather will also play a large role in how quickly your divided cannas grow. Cannas thrive in heat. If you have a cool, cloudy spring, your cannas might sit quietly in the ground for a few weeks without much visible growth. As soon as the overnight temperatures consistently stay above 60°F and the sun comes out, you will see them begin to jump.
By the second year after division, your new plants will be fully established and likely ready to be divided again if they are in a high-growth environment. This cycle of growth and division is part of what makes canna gardening so enjoyable.
What to Do Next:
- Check your zones: Determine if you need to start your rhizomes indoors based on your local last frost date.
- Gather tools: Ensure you have a sharp knife and some rubbing alcohol for cleaning the blade.
- Prepare the spot: Choose a sunny location and enrich the soil with a bit of compost.
- Monitor the eyes: Wait for those reddish growth points to appear before you start cutting.
Conclusion
Splitting canna bulbs is a simple, cost-effective way to fill your garden with tropical color. By taking the time to divide your rhizomes every few years, you ensure that your plants remain healthy, vigorous, and full of blooms. It is a rewarding task that allows you to see the incredible life cycle of these plants up close.
At Longfield Gardens, we want to help you grow the most beautiful garden possible. Whether you are expanding a collection of variegated foliage types or adding more bright blossoms to your backyard, the process of division is your best tool for success. Remember to be patient with the spring weather, give your plants plenty of sun, and enjoy the spectacular display that follows.
Dividing your cannas is not just about getting more plants; it is about giving your garden a fresh start and ensuring that every plant has the space and resources it needs to shine.
We invite you to explore our selection of premium canna rhizomes and start planning your most vibrant summer garden yet. If you have questions about delivery timing or order status, our Shipping Information page has the details.
FAQ
Does every piece of the canna rhizome need an "eye" to grow?
Yes, each division must have at least one "eye" or growth bud to produce a new plant. These eyes are the points from which the stems and leaves emerge. While one eye is enough, we recommend leaving two or three eyes on each piece to ensure the plant grows in full and robust during its first season.
Can I split canna bulbs in the fall instead of the spring?
While you can technically divide them in the fall after digging them up, it is generally safer to wait until spring. Dividing in the spring allows you to see which eyes are the healthiest and most active. Additionally, keeping the rhizomes in larger clumps during winter storage helps prevent them from drying out too much.
What should I do if my canna rhizome feels soft or mushy?
If a rhizome feels mushy or has a foul smell, it may be experiencing rot, usually caused by excess moisture. When splitting your bulbs, simply cut away any soft sections and discard them. Only replant the firm, healthy pieces that have clear, vigorous growth buds.
How many years should I wait between splitting my canna plants?
Most cannas benefit from being divided every 2 to 3 years. You will know it is time to split them if the clump has become very large, the flowers are getting smaller, or the plant seems to be struggling for space. Dividing them regularly keeps the plants young and ensures maximum flower production.