Introduction
The vibrant, tropical flair of cannas is a highlight of the summer garden. Their bold foliage and brilliant flowers bring a sense of the exotic to any landscape, whether they are planted in garden beds or large patio containers. As the growing season winds down, many gardeners look forward to preserving these beautiful plants so they can enjoy them again next year.
At Longfield Gardens, we want to help you make the most of your garden by ensuring your favorite plants thrive season after season. Storing canna "bulbs"—which are technically called rhizomes—is an easy and rewarding way to expand your collection without starting from scratch every spring. It is a simple process that fits perfectly into a relaxed fall garden cleanup routine.
This guide will walk you through the straightforward steps of lifting, cleaning, and storing your cannas for the winter. Whether you are a beginner or a seasoned gardener, you will find that these tropical beauties are remarkably resilient. With just a little bit of care, you can keep your cannas safe and dormant until the warmth of spring returns.
Understanding Canna Rhizomes
Before we dive into the storage process, it is helpful to know what we are working with. While most people refer to them as bulbs, cannas actually grow from rhizomes. A rhizome is a thick, fleshy underground stem that grows horizontally. It stores the energy and nutrients the plant needs to sprout and grow when the weather warms up.
These rhizomes are incredibly productive. During a single growing season, a small piece can grow into a large, heavy clump. This means that when you dig them up in the fall, you often end up with many more plants than you started with in the spring.
It is also important to remember that cannas are tropical plants. They love heat and sun, but they cannot survive freezing temperatures in the ground. In most parts of the United States, especially in zones 7 and colder, these rhizomes need to be lifted and brought indoors to a frost-free environment for the winter. For more guidance, see this canna growing zone guide.
When to Start the Storage Process
Timing is one of the most important parts of successful canna bulb storage. You want to give the plants as much time as possible to store energy in their rhizomes. This energy is what fuels the first flush of growth next year.
The best time to dig up your cannas is shortly after the first light frost of the autumn. You will know it is time when the lush green or bronze leaves turn black or brown and begin to wither. This frost acts as a natural signal to the plant that it is time to go dormant.
If your area does not experience an early frost, you can wait until the foliage starts to yellow naturally in late autumn. However, it is vital to get the rhizomes out of the ground before the soil itself freezes. Once the ground freezes hard, the moisture inside the rhizomes can turn to ice, which damages the plant tissue and prevents it from growing back.
Key Takeaway: Wait for the first frost to turn the foliage brown before digging. This ensures the plant has stored the maximum amount of energy for next year.
Preparing to Dig
Once the frost has arrived, you can begin the lifting process. Start by cutting back the foliage. Use a pair of sharp, clean garden shears to cut the stalks down to about 2 or 3 inches above the soil line. Leaving a small amount of the stalk gives you a "handle" to hold onto and helps you keep track of where the rhizomes are located as you dig.
Before you put your shovel in the ground, clear away any mulch or debris from around the base of the plant. This gives you a clear view of the area and prevents you from accidentally burying the rhizomes under extra soil or mulch.
It is also a good idea to have your storage supplies ready. You will want a sturdy garden fork or spade, a place to let the rhizomes dry, and your preferred storage containers. Having everything on hand makes the process go quickly and keeps your workspace organized.
The Right Way to Lift Cannas
Digging up canna rhizomes requires a gentle touch. Because they are fleshy and full of moisture, they can be bruised or sliced if you are too aggressive with your tools. Wounds on the rhizomes can lead to rot during storage, so the goal is to lift them out as cleanly as possible.
Instead of digging right next to the stalks, start your circle about 6 to 12 inches away from the center of the clump. This ensures you stay clear of the main mass of rhizomes. Using a garden fork is often better than a spade because the tines are less likely to slice through the roots.
Push your tool deep into the soil and gently pry upward. Work your way around the entire clump, loosening the soil as you go. Once the clump feels loose, you can lift the entire mass out of the ground. Don't be surprised if the clump is heavy; cannas are very efficient at growing large root systems in a single season.
Lifting Steps for Success
- Cut back foliage: Trim stalks to 3 inches above the soil.
- Give them space: Start digging 10 inches away from the base.
- Lifting: Use a garden fork to gently pry the clump upward.
- Shake it off: Gently remove large chunks of loose soil by hand.
Cleaning and Curing Your Rhizomes
After the rhizomes are out of the ground, they need a little bit of cleaning before they go into storage. Start by gently shaking the clump to remove loose soil. You can use your hands to brush away more dirt, but avoid scrubbing too hard, as the "skin" on the rhizomes can be quite thin.
Some gardeners prefer to rinse their rhizomes with a garden hose to get them perfectly clean. This makes it easier to spot any signs of damage or pests. If you choose to wash them, be extra careful to let them dry completely afterward.
Curing is the process of letting the rhizomes air dry before they are packed away. This step is essential because it allows the outer layer to toughen up and any small nicks to "scab" over. Place your cleaned rhizomes in a well-ventilated area that is out of direct sunlight and protected from rain and frost. A garage, shed, or covered porch works well. This canna harvesting and storage guide offers another storage overview.
Let the rhizomes dry for two to seven days. They should feel dry to the touch, and any remaining soil should be easy to brush away. Once they are dry, you can trim off any long, stringy roots that are still attached to the main rhizome.
Dividing for More Plants
One of the best things about canna bulb storage is the opportunity to divide your plants. Since cannas multiply so quickly, you will likely have a much larger clump than what you originally planted. Dividing them makes storage more manageable and gives you more plants to use in the spring.
You can divide your cannas either in the fall before you store them or in the spring before you plant them. Many people find it easier to do in the fall when the rhizomes are already out of the ground.
To divide them, look for the "eyes" on the rhizomes. These look like small, pointed bumps or buds. Each piece you save should have at least two or three healthy eyes. You can often pull the rhizomes apart by hand, but if the clump is very dense, use a clean, sharp knife to cut them into sections.
Allow any fresh cuts to dry and callouse for an extra day before packing them away. This simple step helps prevent moisture from entering the cut and causing rot during the long winter months.
Choosing the Best Storage Medium
How you pack your cannas is just as important as where you keep them. The goal is to keep them dormant, which means they need to stay cool, dark, and slightly moist—but never wet. If they get too dry, they will shrivel up. If they stay too wet, they will rot.
There are several popular materials you can use to pack your canna rhizomes. Each has its own benefits, and the best choice often depends on what you have available.
Peat Moss or Coconut Coir
These are popular choices because they hold a tiny bit of moisture without feeling damp. Place a layer of peat moss in the bottom of a plastic bin or cardboard box, nestle the rhizomes inside so they aren't touching each other, and then cover them with more peat.
Wood Shavings or Sawdust
If you have access to untreated wood shavings (like the kind used for pet bedding), these work wonderfully. They provide excellent insulation and help regulate moisture levels throughout the winter.
Newspaper
For a very simple approach, you can wrap individual rhizomes in several layers of dry newspaper. This keeps them separated and provides a breathable barrier. Place the wrapped rhizomes in a single layer inside a crate or box.
Perlite or Vermiculite
These lightweight minerals are great for storage because they are sterile and provide excellent aeration. They are particularly helpful if your storage area tends to be a bit more humid, as they won't mold or decay.
Key Takeaway: Use a packing material like peat moss or wood shavings to keep rhizomes from touching and to maintain a steady, low level of moisture.
The Ideal Storage Environment
Once your cannas are packed, they need a home for the winter. The perfect spot is a location that stays consistently cool but never reaches freezing temperatures.
The ideal temperature range is between 45°F and 55°F. If the temperature stays too warm (above 60°F), the cannas might think it is spring and start to sprout prematurely. If it drops below 40°F, you risk chilling the rhizomes, which can affect their vigor.
Common storage locations include:
- Unheated Basements: Usually the most consistent environment for home gardeners.
- Crawl Spaces: These often stay at the perfect temperature but check for pests.
- Root Cellars: Ideal for both temperature and humidity.
- Attached Garages: These can work, but be careful that the temperature doesn't drop too low during a cold snap.
Regardless of where you store them, keep the containers off the cold floor. Placing your boxes or bins on a shelf or a wooden pallet provides an extra layer of insulation and keeps them away from potential dampness.
Monitoring Your Cannas During Winter
Even though the rhizomes are dormant, they still need a little bit of attention during the winter. It is a good practice to check on them about once a month. This small effort can save your entire collection if something starts to go wrong.
When you check your storage bins, look for two things: rot and shriveling. If you see any soft, mushy spots or notice a foul smell, remove the affected rhizome immediately. Rot can spread quickly from one piece to another, so catching it early is vital.
On the other hand, if the rhizomes look very wrinkled or feel extremely light and brittle, they may be drying out too much. If this happens, use a spray bottle to lightly mist the packing material with water. You don't want it to be wet—just a tiny bit of humidity is enough to plump the rhizomes back up.
Special Tips for Container Cannas
If you grow your cannas in pots, you have a shortcut available to you. Instead of digging the rhizomes out of the soil, you can simply store the entire pot. This is often the easiest way to overwinter cannas, especially for smaller varieties. For more information, read this guide to planting canna lily bulbs in pots.
Once the first frost has blackened the foliage, cut the stalks back to the soil level as you would with garden-planted cannas. Move the entire pot into a cool, dark, frost-free area like a basement or garage. Stop watering the pot entirely. The soil will dry out, and the plant will go into deep dormancy.
In the spring, you can bring the pot back out into the sun, give it a fresh layer of compost or fertilizer, and start watering again. Eventually, the pot will become crowded with rhizomes, and you will need to tip it out and divide the plants, but you can often go two or three years before this becomes necessary.
Preparing for Spring Planting
When the days start to get longer and the threat of frost passes, 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 if you want to get a head start on the season.
Check the rhizomes one last time before planting. They should feel firm and heavy. If you didn't divide them in the fall, you can do so now. Plant them about 3 to 4 inches deep in rich, well-draining soil. For more detail, see this guide to canna planting depth.
Remember that "drainage" simply refers to how fast water leaves the soil. Cannas love moisture, but they don't like to sit in soggy, stagnant mud. Using a high-quality potting mix or amending your garden beds with organic matter will help provide the perfect environment for them to thrive.
Spring To-Do List
- Check for firmness: Discard any pieces that feel hollow or soft.
- Wake them up: Bring rhizomes into a warmer area to signal spring.
- Start early: Pot them up indoors 4 weeks before the last frost for earlier blooms.
- Wait for warmth: Only move them outside once the soil is warm to the touch.
Why Canna Storage is Worth the Effort
While it might seem like an extra step in your fall routine, storing your canna rhizomes is one of the most satisfying parts of gardening. It allows you to build a personal connection with your plants, watching them grow from small pieces into massive, flowering displays year after year.
By taking a few minutes to lift and store them correctly, you are preserving the investment you made in your garden. You also get the joy of sharing your extra divisions with friends and neighbors. There is something truly special about being able to say that the beautiful tropical flower in your yard has been part of your garden for years.
At Longfield Gardens, we believe that gardening should be a rewarding and accessible experience. Successful canna bulb storage is a perfect example of how a few simple, thoughtful steps can lead to a lifetime of garden beauty.
Conclusion
Storing your cannas for the winter is a straightforward process that rewards you with bigger, better displays every year. By following the natural cues of the seasons and providing a safe, cool place for your rhizomes to rest, you ensure that your garden remains a vibrant tropical retreat. It is a wonderful feeling to pull those healthy, firm rhizomes out of storage in the spring and know that another season of spectacular color is just around the house.
- Wait for the first frost to signal dormancy before you start digging.
- Cure the rhizomes for a few days to let the skin toughen up.
- Choose a cool, dry spot that stays between 45°F and 55°F.
- Check monthly to ensure they stay healthy and firm throughout the winter.
"Gardening is a cycle of growth and rest. By caring for your cannas during their winter nap, you are setting the stage for a magnificent performance next summer."
We are here to support your journey every step of the way, providing high-quality plants and the practical advice you need to succeed. Enjoy the quiet of the winter, and get ready for the excitement of spring!
FAQ
Can I leave my cannas in the ground if I live in a warm climate?
If you live in USDA hardiness zones 8 through 11, you can generally leave your canna rhizomes in the ground all year. In zone 7, they may survive with a thick layer of mulch for insulation, but lifting them is the safest way to ensure they return. For gardeners in zones 6 and colder, digging them up for indoor storage is necessary to protect them from freezing. This guide to leaving canna bulbs in the ground provides additional information.
What should I do if my stored cannas start growing in the middle of winter?
If you see sprouts appearing while the cannas are still in storage, it usually means the temperature in your storage area is too warm. Try to move them to a cooler location that stays below 55°F but above freezing. If the sprouts are small, they will likely survive until spring; just be careful not to break them off when you finally move them to the garden.
Do I need to wash the soil off the rhizomes before storing them?
While you don't have to wash them, removing the bulk of the soil is highly recommended. Soil can hold excess moisture which might lead to rot, and it can also hide pests or diseases. Most gardeners find that shaking off the loose dirt and then allowing them to dry is sufficient, but a gentle rinse can make the process cleaner if you have a good place to let them dry afterward.
My canna rhizomes look shriveled and dry in February. Are they dead?
Not necessarily! It is normal for rhizomes to lose some moisture during their dormant period. If they are slightly wrinkled but still feel relatively firm when squeezed, they are likely just fine. You can lightly mist your packing material with water to provide a tiny bit of humidity, but avoid soaking them, as they cannot process much water while they are dormant.
