Table of Contents
- Introduction
- Understanding Canna Rhizomes
- Do You Have to Dig Up Canna Bulbs?
- The Best Time to Dig Up Your Cannas
- Step-by-Step Guide to Digging Canna Rhizomes
- Curing and Preparing for Storage
- How to Store Canna Bulbs Successfully
- Monitoring Your Rhizomes Through Winter
- Growing Cannas in Containers
- Dividing Your Cannas for More Plants
- Preparing to Replant in the Spring
- Common Myths About Digging Cannas
- Managing Pests and Health
- The Longfield Gardens Perspective
- Conclusion
- FAQ
Introduction
There is something undeniably magical about the way canna lilies transform a standard backyard into a lush, tropical sanctuary. With their towering heights, paddle-shaped leaves, and vibrant blooms in shades of sunset orange and fiery red, these plants bring a bold energy to any landscape. At Longfield Gardens, we believe that every gardener should experience the joy of growing these architectural wonders, regardless of where they live. For gardeners looking for a bigger display, the Tall Cannas collection is a great place to start.
If you have fallen in love with these sun-loving giants, you might be wondering about their long-term care. Specifically, do you have to dig up canna bulbs at the end of the season? The answer depends mostly on your local climate and how you want to manage your garden for the following year.
This guide will explain which regions require lifting cannas for the winter, the easiest ways to store them, and how to tell if your plants can safely stay in the ground. Whether you are a beginner or a seasoned gardener, understanding these basics ensures your cannas return bigger and better every summer. For a broader look at planting and growing, see All About Cannas.
Understanding Canna Rhizomes
Before we dive into the "how" and "when," it is helpful to clarify what we are actually digging up. While most gardeners use the term "bulbs," cannas actually grow from rhizomes. A rhizome is a fleshy, horizontal underground stem that stores energy and nutrients for the plant.
Unlike a true bulb, such as a tulip or daffodil, which has a distinct rounded shape and layers, a rhizome looks more like a piece of ginger root. These thick stems spread out under the soil surface, sending up new shoots as they grow. This growth habit is why cannas are so easy to propagate. You can simply cut a large rhizome into smaller pieces, and as long as each piece has at least one "eye" or growth point, it will grow into a brand-new plant.
Do You Have to Dig Up Canna Bulbs?
The decision to dig up your cannas is almost entirely based on your USDA hardiness zone. Cannas are tropical and subtropical plants, meaning they thrive in heat but cannot tolerate freezing soil. Longfield Gardens explains how zone-based timing affects canna care on its Shipping Information page.
When You Can Leave Them in the Ground
If you live in USDA zones 8 through 10, you are in luck. In these warmer regions, cannas are generally considered "hardy" and can stay in the garden year-round. The ground rarely freezes deep enough to damage the rhizomes. In zone 7, many gardeners find success leaving them in the ground if they provide a thick layer of mulch (about 4 to 6 inches of straw or wood chips) to insulate the soil.
When Digging Is Required
For gardeners in zones 2 through 6, cannas are treated as "tender perennials" or annuals. If the rhizomes are left in the ground during a hard freeze, the water inside the fleshy stems will turn to ice, causing the cells to burst. This leads to rot once the ground thaws, and the plant will not return in the spring. If you want a variety that makes a strong summer statement, Canna Tall Pretoria is one of the garden standouts Longfield Gardens offers.
If you live in these colder zones and want to save your plants for next year, you must dig them up before the ground freezes solid. Many people find this process incredibly rewarding, as it allows them to multiply their collection for free each year.
Key Takeaway: If your winter temperatures regularly drop below freezing and stay there, your canna rhizomes will likely perish unless they are lifted and stored in a frost-free environment.
The Best Time to Dig Up Your Cannas
Timing is everything when it comes to lifting tender plants. You want to give the rhizomes as much time as possible to store energy from the sun, but you must act before the deep freeze sets in.
The ideal signal to start digging is the first light frost of autumn. You will notice the large, lush leaves turn brown or black almost overnight after a frost. This is perfectly normal and does not mean the plant is dead; it simply means the foliage has finished its job for the season.
Once the tops have been "nipped" by frost, you should aim to dig them up within a week or two. If you live in an area where frost is rare but winters are still too cold for cannas, you can simply wait until the plants stop growing and begin to yellow in late autumn.
Step-by-Step Guide to Digging Canna Rhizomes
Digging up cannas is a straightforward process that requires only a few basic tools. The goal is to move the rhizomes from the garden to storage without causing unnecessary damage.
1. Cut Back the Foliage
Start by using a pair of sharp garden shears or a lopper to cut the stems back. Leave about 2 to 4 inches of the stem attached to the rhizome. This provides a "handle" for moving the plants and makes it easier to identify the clumps during the digging process.
2. Loosen the Soil
Using a garden fork or a sturdy shovel, begin digging around the perimeter of the plant. Canna rhizomes can spread quite wide, so start your digging about 10 to 12 inches away from the main stems. This helps avoid accidentally slicing through the fleshy roots.
3. Lift the Clump
Gently pry the clump upward from several sides until it releases from the soil. Once the clump is loose, lift it out of the ground. Don't be surprised by the size—a single canna rhizome planted in the spring can grow into a massive, heavy clump by autumn!
4. Remove Excess Soil
Shake the clump gently to remove large chunks of dirt. You can use your hands to brush away loose soil, but avoid being too aggressive. It is not necessary to wash the rhizomes with water. In fact, keeping them dry helps prevent fungal issues during storage.
5. Inspect and Label
Check each clump for signs of damage or soft spots. If a section of the rhizome feels mushy or looks diseased, trim it off with a clean knife. If you are growing several different varieties of cannas, now is the time to label them. Use a permanent marker to write the variety name directly on the stem or attach a small tag.
What to Do Next:
- Gather your shovel, garden fork, and shears.
- Wait for the first frost to turn the leaves brown.
- Cut the stems to 3 inches above the soil line.
- Carefully lift the clumps, keeping the rhizomes intact.
- Label your varieties immediately to avoid confusion in the spring.
Curing and Preparing for Storage
Curing is a simple but vital step in the process. It involves letting the rhizomes dry out slightly so the outer skin can toughen up. This acts as a natural barrier against rot while they are tucked away for the winter.
Place your lifted canna clumps in a dry, shaded area—like a garage, shed, or covered porch—for 2 to 3 days. Do not leave them in direct sunlight, as this can cause them to dry out too much. You want the outer surface to feel dry to the touch, but the rhizome itself should still feel firm and heavy.
Once cured, you can decide whether to divide the clumps now or wait until spring. Most gardeners prefer to store the clumps whole and divide them in the spring when the "eyes" (the small bumps where new growth starts) are more visible. If you are short on space, the How to Grow Canna Bulbs in Containers guide has helpful ideas for keeping cannas in pots.
How to Store Canna Bulbs Successfully
The environment where you keep your cannas over winter determines if they will thrive when replanted. The ideal storage spot is cool, dark, and dry, but never freezing.
Choosing a Storage Container
You can use cardboard boxes, plastic crates with ventilation, or even paper bags. Avoid using airtight plastic bins, as these trap moisture and almost always lead to mold and rot.
Using Storage Media
To keep the rhizomes from shriveling, it is helpful to pack them in a "medium" that regulates moisture. Popular choices include:
- Peat moss: Excellent at holding just enough moisture.
- Vermiculite or Perlite: Provides good insulation.
- Wood shavings: Simple, clean, and breathable.
- Dry sand: Traditional and effective, though heavy.
Layer the bottom of your container with a few inches of your chosen medium. Place the rhizomes on top, making sure they aren't touching each other. Cover them completely with more medium. This "nesting" approach protects them from temperature fluctuations.
Finding the Right Temperature
The "sweet spot" for canna storage is between 40°F and 50°F (4°C to 10°C). An unheated basement, a crawl space, or a corner of an attached garage that stays above freezing are all excellent locations. If the area is too warm, the rhizomes may try to start growing too early. If it is too cold, they may suffer frost damage.
Monitoring Your Rhizomes Through Winter
Storing cannas is not a "set it and forget it" task. We recommend checking on your stored rhizomes about once a month. This small effort can save your entire collection if issues arise.
When you check them, look for two things:
- Signs of Rot: If you find a rhizome that feels soft, mushy, or has a foul smell, remove it immediately. This prevents the rot from spreading to the healthy rhizomes nearby.
- Signs of Shriveling: If the rhizomes look very wrinkled or feel lightweight, they are losing too much moisture. Use a spray bottle to lightly mist the storage medium with water. You don't want it wet—just slightly damp to the touch.
By staying proactive, you ensure that your plants remain healthy and ready to burst into growth the moment spring arrives.
Growing Cannas in Containers
If the idea of digging up plants every year feels like a lot of work, consider growing your cannas in containers. This is a fantastic strategy for those in colder climates.
When you grow cannas in pots, the "digging" process is replaced by simply moving the pot. Once the foliage has died back after a frost, cut the stems down as usual. Instead of digging the rhizomes out of the soil, move the entire pot into a frost-free area like a basement or garage.
The soil in the pot acts as a natural insulator and storage medium. Keep the soil dry throughout the winter. In the spring, you can bring the pot back out, refresh the top few inches of soil, and start watering to wake the plant up. For a colorful container choice, Canna Short Orange Chocolate brings bold foliage and bright flowers in a compact size.
Dividing Your Cannas for More Plants
One of the best things about cannas is how quickly they multiply. A single rhizome can often produce three or four new plants in just one growing season. At Longfield Gardens, we love how this allows gardeners to expand their displays or share plants with friends and neighbors.
The best time to divide is in the early spring, right before you are ready to plant. When you pull your rhizomes out of storage, look for the "eyes"—these are the small, rounded nubs that look like the eyes on a potato. For gardeners who want a ready-made mix, the Canna Assorted Mix is an easy way to add variety to the garden.
To divide, use a clean, sharp knife to cut the rhizome into sections. Each section must have at least one healthy eye. After cutting, let the pieces sit for a day or two so the "wound" can callouse over. This simple step protects the piece from rotting once it is placed in damp spring soil.
Preparing to Replant in the Spring
When the days begin to lengthen and the danger of frost has passed, it is time to bring your cannas back into the light.
Waking Them Up Indoors
If you have a short growing season, you can get a head start by "starting" your cannas indoors about 4 to 6 weeks before the last frost date. Place the rhizomes in pots with potting soil and keep them in a warm, sunny spot. By the time the weather is warm enough to plant outside, you will already have established plants with several inches of growth.
Outdoor Planting
Cannas love three things: sun, water, and rich soil. Choose a spot that receives at least 6 to 8 hours of direct sunlight. They are "heavy feeders," so mixing some compost or well-rotted manure into the planting hole will give them the nutrients they need to reach their full potential. For a detailed planting reference, How Deep Do You Plant Canna Lily Bulbs? explains the depth and spacing basics.
Plant the rhizomes about 2 to 4 inches deep and space them 1 to 2 feet apart, depending on the variety. Larger types need more room to breathe, while dwarf varieties can be planted more closely.
Common Myths About Digging Cannas
There is a lot of conflicting advice online about cannas, which can make the process seem more complicated than it really is. Let’s clear up a few common misconceptions.
Myth: You must wash the rhizomes before storing them. Actually, washing them can introduce too much moisture, which is the primary cause of winter rot. Shaking off the dirt is enough.
Myth: Cannas won't bloom the first year if you start from small divisions. As long as the rhizome section has a healthy eye and receives plenty of sun and water, it will almost always bloom in its first season. Cannas are incredibly fast growers.
Myth: You have to use expensive storage chemicals. You don't need fungicides or special powders to keep cannas healthy. Good airflow, the right temperature, and a dry storage medium are usually all that is required for success.
"Gardening with cannas is a journey of color and height. While the act of lifting them for winter requires a little effort, the reward of seeing those familiar tropical leaves emerge each spring makes it one of the most satisfying rhythms of the gardening year."
Managing Pests and Health
Cannas are generally very tough plants, but keeping them healthy throughout the summer makes the overwintering process more successful. Healthy plants produce stronger rhizomes with more stored energy.
The most common issue for cannas is the canna leaf roller, a small caterpillar that rolls the leaves shut. While they don't usually kill the plant, they can make the foliage look tattered. Keeping your plants well-watered and fed helps them outgrow any minor pest damage.
When it comes to the rhizomes themselves, the main threat is moisture. During the growing season, cannas love water—they can even grow in the shallow edges of a pond! However, during their dormant winter phase, moisture is their enemy. Ensuring they are stored in a dry medium is the single most important factor in keeping them healthy until spring.
The Longfield Gardens Perspective
We believe that gardening should be a rewarding experience that connects you with the natural cycles of the seasons. Caring for cannas is a great way to practice "right plant, right place." By understanding your zone and the needs of these tropical beauties, you take the guesswork out of their care.
Our trial gardens allow us to observe how different varieties perform and how their rhizomes develop over a season. We’ve found that providing a little extra care during the digging and storage phase pays off ten-fold when the summer heat arrives and your garden is transformed into a towering display of color. If you want to see more of what we grow, visit our About Us page.
Conclusion
So, do you have to dig up canna bulbs? If you live in a climate with freezing winters, the answer is a resounding yes—at least if you want to keep your favorite varieties for next year. While it does require a bit of seasonal work, the process is simple and deeply satisfying. It turns a one-time purchase into a lifelong collection.
By following these simple steps, you can enjoy the tropical beauty of cannas year after year:
- Identify your USDA zone to determine if lifting is necessary.
- Wait for the first frost to signal the start of the digging season.
- Cure and store your rhizomes in a cool, frost-free location.
- Check on them periodically to ensure they aren't rotting or drying out.
The beauty and height that cannas bring to the garden are worth every bit of effort. We invite you to explore the many colors and textures available and start your own tropical tradition this season. To browse the full selection, shop cannas at Longfield Gardens and let us help you create the landscape of your dreams.
FAQ
What happens if I don't dig up my cannas and it freezes?
If the ground freezes deep enough to reach the rhizomes, the cells inside the "bulb" will burst. This leads to the rhizome turning into a mushy, rotten mess as the soil warms up in the spring. In zones 6 and colder, it is almost certain that the plants will not survive the winter if left unprotected.
Can I store canna rhizomes in the refrigerator?
While a refrigerator is cool, it is often too cold (usually around 35°F) and too dry for long-term canna storage. Additionally, fruits and vegetables in the fridge release ethylene gas, which can damage the dormant rhizomes. A cool basement or garage between 40°F and 50°F is a much better environment. Longfield Gardens also notes shipping and handling details on its Shipping Information page.
Do I need to wait for a frost before I dig them up?
You don't have to wait for a frost, but it is the easiest way to know the plant has finished its growing cycle. If you need to clear your garden beds early, you can dig them up before the frost, but be sure to let the foliage wither naturally in a cool spot so the energy can return to the rhizome. If you want more container-specific advice, the How to Grow Canna Bulbs in Containers guide is a useful companion.
How do I know if my stored canna rhizomes are still good in the spring?
Healthy rhizomes should feel firm and heavy, similar to a fresh potato. If they are extremely lightweight, brittle, or feel like a hollow shell, they have dried out too much. If they are soft and mushy or have visible mold growth, they have likely rotted and should be discarded. For a quick reminder on planting depth before spring arrives, see How Deep Do You Plant Canna Lily Bulbs?.