Table of Contents
- Introduction
- Understanding Canna Rhizomes
- When to Dig Up Canna Bulbs
- Tools and Materials You Will Need
- The Digging Process: Step-by-Step
- Cleaning and Curing Your Cannas
- To Divide or Not to Divide?
- Packing Your Cannas for Storage
- Finding the Perfect Winter Home
- Winter Maintenance and Monitoring
- Special Advice for Container-Grown Cannas
- Zone Considerations: Do You Really Need to Dig?
- Bringing Cannas Out of Storage in Spring
- Conclusion
- FAQ
Introduction
There is nothing quite like the tropical flair that cannas bring to a summer garden. Their bold, oversized foliage and vibrant, torch-like flowers make every backyard feel like a private island getaway. At Longfield Gardens, we believe these spectacular plants are one of the most rewarding additions to any landscape. While they thrive in the heat of summer, most gardeners in the United States face a common question as the season winds down: how do we keep these beauties alive for next year? If you're planning ahead, start with our Cannas Bulbs for Sale collection.
Storing your cannas for the winter is a simple and satisfying way to preserve your favorite varieties and save money on next year’s garden. This process is often called "overwintering," and it is much easier than many people think. Whether you are a beginner or a seasoned gardener, learning to store canna bulbs for winter ensures that your garden will be even bigger and better when spring returns. For a broader care overview, read All About Cannas.
In this guide, we will walk you through the entire process, from the first frost to the final storage spot in your basement or garage. We will cover how to dig them safely, how to prepare them for their winter nap, and how to keep them healthy until it is time to plant again. With a little bit of care, you can enjoy these tropical treasures for many years to come. For more inspiration, see Fresh Ideas for Growing Cannas.
Understanding Canna Rhizomes
Before we jump into the "how-to," it is helpful to understand what you are actually digging up. While most people call them "canna bulbs," they are technically rhizomes. A rhizome is a thick, fleshy underground stem that grows horizontally. It acts as the plant's energy storage tank. During the summer, the plant packs this rhizome with nutrients and energy.
In colder climates, the plant cannot survive the freezing temperatures of winter. However, the rhizome can survive if it is kept in a cool, dark, and frost-free environment. When you store canna bulbs for winter, you are essentially putting the plant into a state of dormancy, which is a deep sleep. If you like big, dramatic plants, browse our Tall Cannas collection.
The goal of winter storage is to keep these rhizomes "just right"—not so cold that they freeze, and not so wet that they rot. It sounds like a delicate balance, but once you know the steps, it becomes a natural part of your gardening routine.
When to Dig Up Canna Bulbs
Timing is one of the most important parts of successfully overwintering your plants. If you dig them too early, the rhizomes may not have finished storing all the energy they need for next year. If you wait too long, a deep freeze could damage the fleshy tissue.
The First Frost Signal
Nature provides a very clear signal for when it is time to get your shovel. You should wait until the first light frost of the season. A light frost will turn the canna’s lush green or bronze leaves brown or black. This may look a bit sad at first, but it is actually a good thing.
The frost tells the plant that summer is over and it is time to shut down. When the foliage dies back, the energy from the leaves moves down into the rhizome. This final "energy dump" is what gives the plant the strength to sprout vigorously in the spring.
The Safety Window
Ideally, you should dig your cannas within a few days of that first frost. You want to get them out of the ground before the soil itself freezes. While the leaves can handle a bit of ice, the rhizomes cannot. If you live in an area where the ground freezes quickly, keep a close eye on the weather forecast starting in late September or October.
Key Takeaway: Wait for the first frost to turn the leaves brown. This signals the plant to go dormant and ensures the rhizomes are packed with energy for next spring.
What to do next:
- Watch your local weather forecast for the first "freeze warning" or "frost advisory."
- Gather your tools (shovel, garden fork, and pruners) so you are ready when the time comes.
- If a frost is delayed and it is getting very late in the season (late November in many areas), you can go ahead and dig them even if the leaves are still green.
Tools and Materials You Will Need
Having your supplies ready makes the process quick and easy. You don't need expensive equipment to store canna bulbs for winter. Most of these items are already in your garden shed or around your house. If you want a mix of colors and heights, the Canna Assorted Collection is an easy place to start.
- A Garden Fork or Shovel: A garden fork is often preferred because it is less likely to accidentally slice through a rhizome.
- Hand Pruners or Loppers: Use these to cut back the heavy stalks.
- A Garden Hose: For gently rinsing off excess soil.
- Storage Containers: Cardboard boxes, plastic tubs (with the lids left off), or even paper bags work well.
- Storage Medium: This is the material you will pack around the rhizomes. Options include peat moss, perlite, vermiculite, or wood shavings (the kind used for pet bedding).
- Labels and a Marker: It is very easy to forget which variety is which once the leaves are gone!
The Digging Process: Step-by-Step
When you are ready to dig, choose a day when the soil is not overly saturated with water. Working in mud is difficult and makes cleaning the rhizomes much harder.
Step 1: Cut Back the Foliage
Start by cutting the stalks down to about 2 to 4 inches above the soil line. You don't need to save the leaves or the spent flowers. Removing the bulk of the plant makes it much easier to see where the base of the plant is and gives you a "handle" to grab later. You can compost the healthy green stalks, but if the leaves were diseased, it is best to discard them.
Step 2: Loosen the Soil
Cannas grow and expand significantly over a single summer. A small rhizome planted in May can turn into a massive clump by October. Because of this, you should start digging at least 8 to 12 inches away from the base of the stalks. If you want a more manageable fit for beds and containers, take a look at Medium Cannas.
Push your shovel or fork deep into the ground and gently pry upward. Work your way all the way around the plant. The goal is to lift the entire clump out of the ground as one piece.
Step 3: Lift the Clumps
Once the soil is loose, use your hands or your shovel to lift the clump out of the hole. Don't be surprised if the clump is heavy! Canna rhizomes are full of water and can be quite substantial. Shake off as much loose soil as you can while you are still at the garden bed.
Key Takeaway: Be gentle when digging. Nicks and cuts in the rhizomes can lead to rot during the winter. Give the plant plenty of space and lift from underneath.
Cleaning and Curing Your Cannas
Once the rhizomes are out of the ground, they need a little bit of preparation before they go into storage. This stage is often called "curing."
Gentle Cleaning
Most gardeners prefer to rinse their cannas with a garden hose to remove the remaining soil. This makes it much easier to inspect the rhizomes for any signs of damage or pests. It also keeps your indoor storage area much cleaner.
When rinsing, use a gentle stream of water. Avoid using a high-pressure nozzle, as you don't want to tear the thin "skin" of the rhizome. If you have heavy clay soil that sticks to everything, you might need to use your fingers to gently rub the dirt away.
The Curing Phase
Curing is a vital step that many people skip. After washing, the rhizomes are very wet. If you pack them away immediately, the trapped moisture will almost certainly cause them to rot.
Place your cleaned rhizomes in a dry, well-ventilated area that is protected from rain and frost. A garage, a shed, or even a covered porch works well. Spread them out in a single layer on a piece of cardboard or newspaper. Let them dry for several days—usually about 3 to 7 days is enough.
During this time, the outer skin of the rhizome will toughen up slightly, and the cut ends of the stalks will dry out and "callus" over. This callus acts as a protective barrier against disease.
What to do next:
- Cut the stalks to 3 inches.
- Rinse away the soil with a garden hose.
- Spread the rhizomes out in a dry, frost-free spot.
- Leave them alone for about a week until the surfaces feel dry to the touch.
To Divide or Not to Divide?
When you lift your cannas, you will likely notice that they have multiplied. What started as one or two "eyes" (the growing points) might now be a large, tangled mass. You have two choices: you can store the clumps whole, or you can divide them now.
Dividing in the Fall
Some gardeners like to divide their cannas in the fall because the rhizomes are still somewhat flexible. You can snap or cut them into smaller sections. Each section must have at least one "eye" (a small, often pinkish or white bump where next year’s growth will come from) to be viable. If you divide them now, make sure to let the cut pieces cure for an extra day or two so the wounds can dry.
Dividing in the Spring
At Longfield Gardens, we often find it easier to store the clumps whole and divide them in the spring. Large clumps tend to lose moisture more slowly than small, individual pieces. This helps prevent the rhizomes from shriveling up over the winter. In the spring, you can clearly see which eyes are starting to wake up, making it very easy to decide where to make your cuts. For a bold dark-foliage choice next year, consider Canna Tall Tropicanna Black.
Packing Your Cannas for Storage
Now that your cannas are clean, dry, and cured, it is time to pack them away for their long winter nap. The goal here is to provide a stable environment where they won't freeze, but also won't dry out completely.
Choosing a Container
Cardboard boxes are the most popular choice because they are breathable. They allow a tiny amount of air exchange, which helps prevent moisture from building up. You can also use plastic storage bins, but if you do, do not put the lid on tight. Leave it cracked or drill a few air holes in the sides.
The Best Storage Media
You don't want the rhizomes just sitting in an empty box; they will dry out too fast. Instead, you should "nest" them in a storage medium. We recommend using one of the following:
- Peat Moss: This is the gold standard for many gardeners. It holds a tiny bit of moisture but stays fluffy enough to allow air circulation.
- Wood Shavings: Pine shavings (the kind sold for hamster or rabbit bedding) are inexpensive, clean, and work beautifully.
- Vermiculite or Perlite: These are sterile and very effective, though they can be a bit more expensive for large collections.
- Newspaper: If you don't have anything else, you can wrap each individual rhizome in several layers of dry newspaper.
How to Pack the Box
Place a 2-inch layer of your chosen medium at the bottom of the box. Lay your rhizomes on top of the medium. Try to keep them from touching each other; this way, if one starts to rot, the problem won't spread to its neighbors. Cover the rhizomes with more medium until they are completely buried.
Don't forget to include a label! You can write the variety name on a plastic garden tag and tuck it into the box, or simply write the name on the outside of the cardboard.
Finding the Perfect Winter Home
Where you keep your boxes is just as important as how you pack them. Cannas are tropical plants, and their "storage sweet spot" is quite specific.
The Ideal Temperature
The perfect temperature for storing canna bulbs for winter is between 45°F and 55°F.
- If the temperature stays above 60°F, the rhizomes might think it is spring and try to start growing in the dark, which wastes their energy.
- If the temperature drops below 40°F, you are getting too close to the danger zone.
- If they freeze, they will turn to mush and will not grow again.
Common Storage Locations
- Unheated Basements: Usually the best option. They stay cool and relatively humid.
- Attached Garages: These can work well, but be careful. In very cold climates, the edges of a garage can drop below freezing. Keep your boxes on an interior wall or elevated off the concrete floor.
- Crawl Spaces: These often have the perfect temperature and humidity, provided they stay dry.
- Root Cellars: An old-fashioned but highly effective choice.
Key Takeaway: Think of the storage area like a refrigerator for plants. You want it cool and dark, but never freezing.
Winter Maintenance and Monitoring
One of the most common mistakes gardeners make is "set it and forget it." Even in dormancy, canna rhizomes are living things. They require a quick check-up once a month to ensure everything is going well.
The "Squeeze Test"
Once a month, open your boxes and check a few rhizomes. They should feel firm to the touch, similar to a fresh potato.
- If they feel soft or mushy: This is a sign of rot. Remove the affected rhizome immediately and throw it away. If only a small part is mushy, you can sometimes cut the bad part off with a clean knife and let the rest dry out before putting it back.
- If they feel extremely light and shriveled: This means they are losing too much moisture. They shouldn't be bone-dry. If they look like raisins, use a spray bottle to lightly mist the storage medium (the peat moss or shavings) with a tiny bit of water. You don't want the medium wet—just barely damp.
Managing Airflow
If you notice any mold growing on the surface of the medium or the stalks, it usually means the air is too stagnant. Move the boxes to a spot with slightly better circulation or leave the tops of the boxes open for a few days to let excess moisture escape.
Special Advice for Container-Grown Cannas
If you grow your cannas in large pots or decorative containers, you have a shortcut available! You don't necessarily have to dig them up. For a smaller patio-friendly choice, try Canna Short Pink Magic.
When the frost hits and the leaves turn brown, cut the stalks down to the soil line just like you would for garden-grown plants. Instead of digging the rhizomes out, simply move the entire pot into your cool storage area (like the basement or garage).
The soil in the pot will act as the storage medium. You don't need to water the pot at all during the winter. In the spring, you can bring the pot back out, give it a good soak, and the plants will begin to sprout. Every two or three years, you will still need to dump the pot out and divide the rhizomes, as they will eventually become "root-bound" and run out of space to grow.
Zone Considerations: Do You Really Need to Dig?
In the United States, your USDA Plant Hardiness Zone determines whether you need to store canna bulbs for winter or if you can leave them in the ground.
- Zones 8 to 10: In these warm climates, cannas are usually hardy. You can leave them in the ground year-round. Simply cut the dead foliage back in late fall and maybe add a layer of mulch for extra protection.
- Zone 7: This is the "swing" zone. In mild winters, cannas may survive in the ground with a heavy 6-inch layer of mulch. However, a particularly cold or wet winter can kill them. Many gardeners in Zone 7 choose to dig up their favorites just to be safe.
- Zones 3 to 6: In these regions, the ground freezes deep enough to kill the rhizomes. Digging and storing them indoors is a requirement if you want to keep your plants from year to year.
If you are unsure which zone you live in, you can easily find out by checking a Hardiness Zone Map or visiting our website for more information on regional planting.
Bringing Cannas Out of Storage in Spring
The excitement of spring is even better when you know you have a box of healthy cannas ready to go. When the threat of frost has passed and the soil has warmed up to at least 60°F, it is time to replant.
Before planting, take the rhizomes out of the box and give them one final inspection. Discard anything that didn't make it through the winter. This is also the perfect time to divide large clumps. Use a sharp, clean knife to cut the rhizomes into pieces, making sure each piece has at least two or three healthy-looking eyes.
For an even earlier show of flowers, many gardeners "start" their cannas indoors in pots about 4 to 6 weeks before the last frost. Place them in a sunny window or under grow lights. By the time the weather is warm enough to move them outside, you will already have several inches of lush green growth!
Conclusion
Storing canna bulbs for winter is a simple, rewarding task that bridges the gap between the seasons. It transforms a one-summer plant into a lifelong garden companion. By following these steps—waiting for the frost, digging carefully, curing properly, and finding a cool winter home—you ensure that your garden remains a vibrant, tropical sanctuary year after year.
Remember these key steps for success:
- Wait for nature's signal: Let the first frost tell you when to dig.
- Cure before you pack: Drying the rhizomes is the best defense against rot.
- Monitor monthly: A quick check ensures your plants stay firm and healthy.
- Think cool, not cold: Keep your storage area between 45°F and 55°F.
Gardening is all about the joy of growth and the rhythm of the seasons. We hope this guide helps you feel confident in preserving your cannas. If you ever have questions about your plants or need to add new varieties to your collection, see About Longfield Gardens.
At Longfield Gardens, we want every gardener to experience the success of a beautiful, blooming landscape. Taking the time to store your canna rhizomes is a wonderful way to invest in the future beauty of your yard.
Happy gardening, and we look forward to seeing your cannas reach new heights next summer!
FAQ
Should I wash the dirt off my canna rhizomes before storing them?
Yes, it is generally better to gently wash the soil off with a garden hose. Removing the soil allows you to inspect the rhizomes for rot, soft spots, or pests like thrips. Once washed, however, it is critical that you let them "cure" or air-dry for several days so they aren't wet when you pack them away.
What is the best material to pack canna bulbs in for the winter?
The most successful materials are breathable and slightly moisture-retentive, such as peat moss, wood shavings, or vermiculite. These materials help prevent the rhizomes from drying out completely while still allowing enough air circulation to prevent rot. Avoid using airtight plastic bags, as these trap moisture and lead to mold. For more container-growing ideas, see Best Summer Bulbs for Containers.
My stored canna rhizomes look shriveled in February. Are they dead?
If they are slightly shriveled but still feel somewhat firm, they are likely just thirsty. Use a spray bottle to lightly mist the storage medium with water. This will provide just enough humidity to plump them back up without making them wet enough to rot. If they are as dry as a piece of wood and feel very light, they may have dried out too much to recover.
Can I store my cannas in a garage that gets very cold?
A garage can be a good storage spot, but only if the temperature stays above freezing. If your garage frequently drops below 32°F, the rhizomes will freeze and die. To keep them safe in a cold garage, place the boxes on an interior wall that shares heat with the house and keep them off the cold concrete floor by placing them on a shelf or a piece of foam insulation.