Table of Contents
- Introduction
- Understanding Your Gardening Zone
- When to Dig Up Canna Lily Bulbs
- Preparing for the Harvest
- How to Lift Canna Rhizomes Safely
- Cleaning and Inspecting the Bulbs
- The Importance of Curing
- Packing Cannas for Storage
- Finding the Perfect Storage Location
- Monitoring During the Winter
- Handling Container-Grown Cannas
- Dividing Cannas: Fall or Spring?
- Transitioning to Spring
- Common Myths About Canna Storage
- Summary of Winter Storage Steps
- FAQ
- Conclusion
Introduction
There is nothing quite like the tropical flair that canna lilies bring to a summer garden. Their oversized, lush foliage and brilliant blooms in shades of red, orange, and yellow make every yard feel like a private oasis. At Longfield Gardens, we enjoy watching these tall, architectural plants transform sunny borders and large containers into vibrant displays of color. However, as the summer warmth fades into the crisp air of autumn, it is time to think about protecting these tender plants so they can return even stronger next season.
Storing cannas for the winter is a straightforward and rewarding process that allows you to enjoy your favorite varieties year after year. While they are tropical by nature, they are also quite resilient if given the right care during their dormant period. This guide is designed to help home gardeners successfully lift, clean, and store their canna rhizomes—often called "bulbs"—to ensure they stay healthy until spring. If you’re looking for more plant options, start with our Cannas collection.
Whether you are a seasoned gardener or just starting your journey with tropical perennials, you will find that a few simple steps in the fall make a world of difference. By following this easy overwintering process, you can preserve your investment and look forward to another season of spectacular growth. Successful winter storage is all about getting the timing right and providing the perfect environment for a long winter nap.
Understanding Your Gardening Zone
Before you reach for your shovel, it is helpful to know if you actually need to dig up your canna lilies. This decision depends primarily on your USDA plant hardiness zone. Cannas are tropical plants and are typically only hardy in zones 8 through 10. In these warmer climates, the ground rarely freezes deep enough to damage the underground rhizomes. If you live in these regions, you can usually leave your cannas in the ground year-round, perhaps adding a light layer of mulch for extra protection.
For gardeners in zone 7, the situation depends on the specific winter weather and the microclimate of your yard. In many years, cannas in zone 7 will survive if they are buried under six to eight inches of insulating mulch, such as straw or shredded leaves. However, if a particularly harsh winter is predicted, digging them up is the safest way to ensure their survival. For a quick reference, our hardiness zone map can help you check your location.
If you live in zone 6 or colder, the ground will freeze deep enough to kill the rhizomes. In these areas, digging and storing the bulbs indoors is a necessary part of the autumn routine. Because we ship our plants based on your specific zone, you likely already have a good idea of your local climate, but it is always worth checking a USDA plant hardiness zone guide if you have recently moved or are trying cannas for the first time. Our Shipping Information page also explains how zone-based shipping works.
When to Dig Up Canna Lily Bulbs
The most important factor in successful storage is timing. You want to give the plants as much time as possible to store energy in their rhizomes before they go dormant. Throughout the summer and early fall, the leaves are busy photosynthesizing and sending nutrients down to the roots. If you dig them up too early, the rhizomes may be smaller and less vigorous the following year.
The best signal to start the process is provided by nature itself. Wait for the first light frost of the season. You will notice the lush green or bronze foliage turn black or brown almost overnight after a frost hits. This is the plant's way of shutting down for the season. Once the foliage has been "zapped" by frost, the plant is no longer growing, and the energy is safely tucked away underground.
If you live in an area where frost comes very late, you can also look for the foliage to naturally yellow and die back. Aim to have your cannas out of the ground before the soil itself begins to freeze hard. A light surface frost is fine, but a deep freeze that penetrates several inches into the dirt can damage the tender rhizomes.
Key Takeaway: Wait for the first frost to blacken the leaves before digging. This ensures the plant has finished storing energy for the winter and is ready for dormancy.
Preparing for the Harvest
Once the frost has arrived, you can begin the physical work of lifting the bulbs. You will need a few basic tools and materials to make the job easy and efficient:
- A sturdy garden fork or a sharp spade
- A pair of clean garden shears or loppers
- A garden hose with a spray nozzle
- Cardboard boxes or breathable paper bags
- Storage medium (peat moss, vermiculite, or wood shavings)
- A permanent marker for labeling
Start by cutting the foliage back. Use your shears to trim the stalks down to about two to four inches above the soil line. Removing the bulky leaves makes it much easier to see where you are digging and prevents the long stems from getting in your way. Do not worry about being too precise with this cut; the small "handle" of the stem that remains will actually be helpful when you are lifting the clumps.
How to Lift Canna Rhizomes Safely
Canna rhizomes grow horizontally and can spread quite a bit during a single growing season. A small starting bulb can easily turn into a large, heavy clump by October. To avoid accidentally slicing through the rhizomes, it is best to start digging several inches away from the base of the stems.
Insert your garden fork or spade vertically into the soil about six to eight inches away from the center of the plant. Gently rock the tool back and forth to loosen the earth. Work your way in a circle around the entire clump. Once the soil is loose all the way around, gently pry the clump upward from underneath.
Because cannas grow in heavy clusters, the soil can be quite heavy. If the clump is too large to lift at once, you can gently break it into smaller pieces while it is still in the ground, but try to keep the rhizomes intact as much as possible. Lift the clumps out of the hole and shake off the largest chunks of loose soil.
What to Do Next:
- Cut back blackened foliage to 3 inches.
- Circle the plant with a garden fork, staying 8 inches from the center.
- Pry upward gently to lift the entire root mass.
- Shake off loose dirt by hand.
Cleaning and Inspecting the Bulbs
Once the rhizomes are out of the ground, they need a bit of cleaning. While some gardeners prefer to leave a little soil on the roots, rinsing them off makes it much easier to inspect for health issues. Use a garden hose to gently wash away the remaining dirt. Avoid using a high-pressure setting, as the skin of the rhizome can be surprisingly tender and you do not want to bruise or tear it.
After rinsing, take a close look at each clump. You are looking for firm, plump rhizomes. If you find any parts that are soft, mushy, or show signs of rot, use a clean knife to trim those sections away. Healthy canna rhizomes are usually white, tan, or pinkish on the inside.
This is also a great time to check for any garden guests that might be trying to hitch a ride into your storage area. Look for signs of pests and remove them. Starting with clean, healthy material is the best way to ensure your cannas survive the next several months in storage.
The Importance of Curing
Curing is perhaps the most overlooked step in the storage process, but it is vital for preventing rot. Curing is simply a period of air-drying that allows the outer skin of the rhizome to toughen up. This "corking over" creates a protective barrier that keeps moisture in and pathogens out.
Place your cleaned rhizomes in a well-ventilated, dry area that is out of direct sunlight. A garage, a shed, or even a covered porch works well, provided the temperatures stay between 60°F and 80°F. Spread the clumps out in a single layer on a piece of cardboard or a mesh screen.
Let the cannas dry for about seven to ten days. During this time, any remaining moisture on the surface will evaporate, and the cut ends of the stems will dry out. If the weather is particularly humid, you might want to run a small fan to keep the air moving. Once the skin feels firm and the rhizomes are dry to the touch, they are ready for their final winter home.
Key Takeaway: Curing your cannas for a week in a dry, ventilated spot hardens the skin and is your best defense against winter rot.
Packing Cannas for Storage
Now that your rhizomes are clean and cured, it is time to pack them away. The goal of storage is to keep the bulbs dormant and prevent them from either rotting or drying out completely (desiccation). Finding that balance is the key to success.
Choosing a Storage Container
Avoid using airtight plastic containers or sealed plastic bags. These trap moisture and almost always lead to mold and rot. Instead, choose breathable containers like:
- Cardboard boxes
- Paper grocery bags
- Wooden crates
- Plastic bins with large holes drilled in the sides
Selecting a Storage Medium
To maintain the right moisture level, you should surround the rhizomes with a packing material. This medium acts as an insulator and a moisture regulator. Popular choices include:
- Peat Moss: Excellent at holding just enough moisture without being "wet."
- Vermiculite: Great for aeration and very clean to work with.
- Wood Shavings: Often used for pet bedding, these are inexpensive and provide good airflow.
- Newspaper: You can wrap individual rhizomes in layers of dry newspaper.
The Packing Process
Start by placing a two-inch layer of your chosen medium at the bottom of the container. Place a layer of canna rhizomes on top, making sure they are not touching each other. If one bulb develops a problem, you don't want it to spread to the rest of the group. Cover that layer with more medium and repeat the process until the box is full. Finish with a final layer of packing material to completely cover the bulbs.
Don't forget to label your boxes! If you grow different varieties, such as the dark-leaved Canna Tall Australia or the striped Canna Tall Pretoria, you will be very happy in the spring if you know exactly which box is which.
Finding the Perfect Storage Location
The environment where you keep your boxes is just as important as how you pack them. Cannas need a spot that is cool, dark, and dry. The ideal temperature range is between 40°F and 55°F.
If the temperature stays above 60°F, the plants may think it is spring and try to start growing in the dark, which depletes their energy. If the temperature drops below 40°F, there is a risk of freezing, which will turn the rhizomes into mush.
Good locations often include:
- An unheated basement or cellar
- A crawl space
- An attached garage that stays above freezing
- A cool closet in an entryway
Check the temperature of your storage spot with a simple thermometer. Remember that spots near exterior walls or on the floor will be cooler than spots near the ceiling or interior walls.
Monitoring During the Winter
Storing canna lilies is not a "set it and forget it" task. You should check on your bulbs about once a month throughout the winter. This only takes a few minutes but can save your entire collection.
Open the boxes and feel a few of the rhizomes. If they feel firm and plump, everything is going well. If you notice any that are starting to feel soft or smell sour, remove them immediately and discard them. If the rhizomes feel shriveled or very light, they may be drying out too much. In this case, use a spray bottle to lightly mist the storage medium with water. You don't want it to be wet, just slightly damp to the touch.
This monthly check-in allows you to adjust the moisture levels and catch any issues before they become widespread. It is normal to lose a few rhizomes over the winter, but consistent monitoring ensures that the vast majority will make it through to spring.
Handling Container-Grown Cannas
If you grow your cannas in pots, the winter storage process is even easier. You don't necessarily have to dig the bulbs out of the soil. Once the foliage has been hit by frost, cut the stems down to the soil level just as you would for garden-grown plants.
Move the entire pot into a cool, dark, frost-free location like a basement or garage. The soil in the pot will act as the storage medium. You won't need to water the pot during the winter; in fact, the soil should be allowed to stay quite dry to keep the plant in a dormant state. In the spring, you can simply bring the pot back out into the sun, start watering, and watch the new shoots appear. This is a fantastic option for those with limited garden space or for gardeners who want to minimize the physical work of digging. For planting advice and seasonal inspiration, see All About Cannas.
Dividing Cannas: Fall or Spring?
As cannas grow, the rhizomes naturally expand and create new "eyes" or growing points. To keep your plants vigorous and to create new plants for your garden, you will eventually need to divide the clumps. You can do this either in the fall when you are digging them up or in the spring before you replant.
Many gardeners prefer to divide in the spring. By waiting until the end of the winter, you can see exactly which parts of the rhizome are the healthiest and have the strongest-looking eyes. To divide, simply use a sharp, clean knife to cut the rhizome into sections. Each section should have at least two or three prominent eyes. If you choose to divide in the fall, some gardeners like to dust the cut ends with sulfur powder to prevent fungal issues, though this is usually not necessary if the rhizomes are cured properly.
Transitioning to Spring
When the days begin to lengthen and the threat of frost has passed in the spring, it is time to wake up your cannas. This is an exciting time for any gardener. You can start your cannas indoors in pots about four to six weeks before the last frost date to get a head start on the season. This is especially helpful in northern climates with shorter growing seasons.
If you prefer to plant directly into the garden, wait until the soil has warmed up to at least 60°F. Cannas love warm soil and won't do much until the ground feels like summer. Planting them in cold, wet spring soil can lead to rot, so patience is a virtue here. When you are ready, plant the rhizomes about four inches deep with the eyes pointing upward.
At Longfield Gardens, we take pride in providing high-quality plants that are ready to perform. Whether you are starting with new rhizomes or replanting ones you have carefully stored, providing plenty of sun, water, and rich soil will result in a magnificent summer display. We stand behind every order with our 100% Quality Guarantee.
Key Takeaway: For the best start in spring, wait for warm soil (60°F) before planting outdoors, or start them in pots indoors for earlier blooms.
Common Myths About Canna Storage
In the world of gardening, there are many "hacks" and tips that can sometimes be more confusing than helpful. One common myth is that you must wash cannas with a bleach solution before storing. In reality, a simple rinse with plain water and proper curing is usually all that is needed for healthy bulbs.
Another misconception is that cannas need to stay completely dry like a paper bag. While they shouldn't be wet, they are living tissue and need a tiny bit of ambient moisture to keep from turning into sticks. This is why using a medium like peat moss or wood shavings is so effective—it holds just enough moisture to keep the rhizome alive without encouraging mold.
Finally, some believe that if a rhizome has a small spot of mold, the whole thing is ruined. This is rarely the case! Simply cut off the affected area, let the cut dry, and keep a closer eye on it. Cannas are incredibly resilient and want to grow.
Summary of Winter Storage Steps
To ensure your cannas come back beautifully next year, keep these simple steps in mind as the season winds down:
- Timing: Wait for the first frost to blacken the leaves.
- Cutting: Trim stalks to 3 inches before digging.
- Lifting: Dig a wide circle around the clump to avoid damage.
- Cleaning: Rinse gently and inspect for any soft spots.
- Curing: Air-dry in a cool, ventilated area for 7–10 days.
- Packing: Use breathable containers and a medium like peat moss or wood shavings.
- Storage: Keep in a cool (40–55°F), dark, and dry location.
- Checking: Monitor monthly and mist lightly if the medium feels bone-dry.
FAQ
Should I wash the dirt off canna bulbs before storing them?
Yes, it is generally a good idea to gently rinse the soil off with a garden hose. This allows you to inspect the rhizomes for rot or pests and ensures you aren't bringing unwanted garden soil or insects into your indoor storage area. Make sure to let them dry completely during the curing process after washing.
How often should I water canna bulbs during the winter?
You should not "water" them in the traditional sense, as this will cause rot. However, you should check them monthly and if the rhizomes appear shriveled or the packing medium feels very dry, use a spray bottle to lightly mist the surface. The goal is to keep the medium barely damp, not wet.
Can I store canna bulbs in the refrigerator?
While a refrigerator is cool and dark, it is usually too cold and too dry for canna rhizomes. Most refrigerators are set below 40°F, which can damage the tender tropical tissue. Additionally, the lack of airflow and the presence of ripening fruit (which releases ethylene gas) can negatively affect the bulbs' health.
What is the best material to pack canna bulbs in for winter?
Peat moss, vermiculite, and coarse wood shavings are the top choices because they regulate moisture effectively. They provide enough insulation to prevent the bulbs from drying out completely while allowing enough airflow to prevent the buildup of mold and rot.
Conclusion
Taking the time to store your canna lily bulbs is one of the most satisfying "end of season" tasks a gardener can perform. It is a bridge between the seasons, turning the vibrant beauty of your summer garden into a promise for the next year. By understanding your zone, waiting for the right frost signal, and providing a cool, stable environment, you can keep your cannas healthy and ready for action. We at Longfield Gardens are always here to support your gardening journey with quality plants and practical advice. With these simple steps, you can look forward to another season of tropical color and lush growth in your own backyard.
Your canna lilies are a long-term investment in your garden's beauty; a little care in the fall ensures a spectacular show next summer.