Table of Contents
- Introduction
- Knowing When to Dig Your Canna Lilies
- Preparing the Plants for Harvest
- How to Dig Canna Rhizomes Safely
- Cleaning and Rinsing
- The Importance of Curing
- Dividing Your Cannas: Fall or Spring?
- Choosing the Best Storage Medium
- Selecting a Storage Container
- Finding the Ideal Storage Location
- Winter Maintenance and Monitoring
- Storing Container-Grown Cannas
- Transitioning to Spring
- Summary of Canna Storage Steps
- FAQ
Introduction
There is nothing quite like the bold, tropical flair that Tall Cannas bring to a summer garden. These plants are the heavy hitters of the flower bed, offering lush foliage and vibrant blooms even during the hottest days of July and August. At Longfield Gardens, we enjoy how these sun-loving beauties transform a standard yard into a vacation-like retreat. When the season begins to wind down, many gardeners wonder how to keep that tropical magic alive for next year.
Storing canna lily bulbs (which are technically rhizomes) is one of the most rewarding ways to save money and ensure your favorite varieties, like Canna Tall Tropicanna, return even bigger and better. This process is straightforward and achievable for gardeners of any experience level. We will walk you through the simple steps of timing your harvest, preparing the rhizomes for their winter nap, and choosing the best storage method for your home. By following these easy steps, you can look forward to another season of spectacular color.
Knowing When to Dig Your Canna Lilies
The first step in successful storage is getting the timing right. While it may be tempting to tidy up the garden as soon as the weather turns chilly, patience pays off with cannas. These plants use the final weeks of the growing season to pull energy down from their leaves into the underground rhizomes. This stored energy is what fuels the first sprout of growth next spring.
In most parts of the country, the best signal to start the process is the first light frost. If you're not sure which climate zone you garden in, the Hardiness Zone Map is a helpful place to start. You will notice the lush green or bronze leaves turn black or brown after a cold night. This is a natural sign that the plant has finished its work for the year and is entering dormancy. Ideally, you should dig your cannas after this frost but before the ground freezes solid. A hard freeze that reaches deep into the soil can damage the tender rhizomes, so keep an eye on your local weather forecast as late autumn approaches.
If you live in a region where frosts are rare or very late, you can simply wait until the foliage begins to yellow and die back naturally in late autumn. This usually happens when day lengths shorten and temperatures consistently dip. The goal is to give the plant as much time as possible to store food while ensuring the rhizomes are safely out of the ground before the winter dampness sets in.
Key Takeaway: Wait for the first light frost to turn the foliage brown before digging. This ensures the plant has stored enough energy for next year's blooms.
Preparing the Plants for Harvest
Before you reach for your shovel, it helps to prepare the top of the plant. Start by cutting the stalks down. Use a sharp pair of garden shears or a bypass pruner to trim the stems to about 2 or 3 inches above the soil line. Removing the heavy mass of foliage makes the actual digging much easier and allows you to see exactly where the base of the plant sits in the soil. For more details on growing and care, see All About Cannas.
Once the foliage is cleared, take a moment to clear any mulch or debris away from the base. This gives you a clear view of the clump's size. Canna rhizomes can grow surprisingly fast over a single summer. A small piece planted in May can easily turn into a large, heavy mass by October. Knowing the footprint of the clump helps you avoid accidentally slicing through the rhizomes with your tools.
How to Dig Canna Rhizomes Safely
When it comes to lifting the rhizomes, the right tool makes a difference. A garden fork is often the best choice because it allows soil to fall through the tines, but a sturdy garden spade also works well. The key is to avoid "stabbing" the center of the plant.
- Start by placing your tool about 6 to 12 inches away from the base of the stems.
- Push the tool straight down into the soil and gently pry upward to loosen the roots.
- Work your way around the entire clump in a circle, loosening the soil as you go.
- Once the clump feels loose, slide your tool underneath the center and lift the entire mass out of the ground.
If you find the clump is too heavy to lift all at once, you can gently break it into smaller sections while it is still in the hole. However, lifting the whole mass usually keeps the rhizomes protected by a bit of soil during the initial move. Once the clump is on the surface, gently shake it or use your hands to brush away the large chunks of soil. You want to see the rhizomes clearly, but there is no need to scrub them perfectly clean just yet.
Cleaning and Rinsing
After digging, some gardeners prefer to let the clumps sit on the lawn for an hour or two to let the soil dry slightly, making it easier to knock off. Once the bulk of the dirt is gone, you can give them a gentle rinse with a garden hose. Using a soft spray of water helps remove soil from the crevices between the "fingers" of the rhizomes. For more inspiration on how cannas can be used in the garden, read Fresh Ideas for Growing Cannas in Your Garden.
It is important to be gentle during this stage. The skin of a freshly dug canna rhizome is relatively soft and can be easily nicked or bruised. Avoid using high-pressure nozzles or stiff brushes. Simply washing away the excess mud is enough. Removing the soil helps prevent soil-borne fungi from hitching a ride into your storage area and also allows you to inspect the rhizomes for any signs of damage or pests.
The Importance of Curing
Curing is perhaps the most overlooked step in the storage process, but it is vital for success. Curing is the process of allowing the outer skin of the rhizome to dry and toughen up. This "cured" skin acts as a protective barrier, preventing the interior from drying out too fast while also resisting rot-causing moisture.
To cure your cannas, find a spot that is out of direct sunlight but has excellent air circulation. A garage, a covered porch, or a shed works well, provided the temperatures are between 60°F and 80°F. Spread the rhizomes out in a single layer on a piece of cardboard, a wooden pallet, or a screen. Do not stack them, as air needs to reach all sides of the rhizome. If you plan to grow them in pots next year, see How to Grow Summer Bulbs in Containers.
Let the cannas sit for about 7 to 10 days. During this time, the cut ends of the stems will dry and "callus" over. The rhizomes will feel firmer to the touch, and any remaining bits of soil will turn to dry dust. Once they are cured, you can use your fingers to gently snap off any remaining dried roots or loose bits of old stem.
What to do next:
- Move the cleaned rhizomes to a dry, shaded area.
- Spread them out so they are not touching.
- Wait 7 to 10 days until the skins feel dry and tough.
- Check for any soft spots and discard any unhealthy pieces.
Dividing Your Cannas: Fall or Spring?
Because cannas are such vigorous growers, you will likely need to divide the clumps every year or two. You can do this either in the fall after curing or in the spring before planting. Many gardeners prefer to do it in the fall because it makes the clumps smaller and easier to pack into storage containers. To see a mid-size option, browse Medium Cannas.
When dividing, look for the "eyes" or growing points. These are the small, rounded bumps on the surface of the rhizome where new stems will emerge. Each division should have at least two or three healthy eyes and a solid piece of rhizome attached. You can usually snap the sections apart by hand, or you can use a clean, sharp knife. If you use a knife, let the cut pieces dry for an extra day or two so the fresh wounds can callus over before they go into final storage.
Choosing the Best Storage Medium
The goal of winter storage is to keep the rhizomes dormant—meaning they should be cool and dry, but not so dry that they shrivel up like raisins. To achieve this balance, most gardeners use a packing medium. This material helps regulate moisture levels around the bulbs.
Peat Moss or Coco Coir
This is the most popular choice because it is lightweight and excellent at managing moisture. You want the peat moss to be "barely damp"—if you squeeze a handful, no water should come out, but it should feel slightly cool to the touch.
Vermiculite or Perlite
These are sterile, mineral-based options that provide great aeration. They are excellent for preventing rot because they don't hold onto excessive moisture as easily as organic materials.
Wood Shavings or Sawdust
Pine shavings (like the kind used for animal bedding) are an inexpensive and effective option. They provide plenty of air pockets while offering enough insulation to keep the temperature stable. A medium-height, container-friendly choice like Canna Medium Banana Punch is a good one to know about next season.
Newspaper or Paper Bags
For gardeners in humid climates, simply wrapping individual rhizomes in several layers of dry newspaper can work well. This allows for maximum breathability while preventing the rhizomes from touching one another.
Selecting a Storage Container
The container you choose should allow for a small amount of gas exchange. You want to avoid airtight plastic bins, as these trap moisture and almost always lead to mold and rot.
- Cardboard Boxes: These are ideal because they are breathable. Line the box with a few layers of newspaper, add a layer of your chosen medium, and then nestle the rhizomes inside.
- Plastic Bins with Holes: If you prefer using plastic bins for durability, drill several half-inch holes in the sides and lid to ensure air can circulate.
- Paper Grocery Bags: For smaller quantities, paper bags are a simple and effective solution. Fill the bag halfway with peat moss, add the rhizomes, and fold the top over loosely.
- Milk Crates or Bread Trays: These provide maximum airflow and are great if you are storing your cannas in a very cool, slightly humid basement.
Finding the Ideal Storage Location
Location is everything when it comes to overwintering tender plants. The "sweet spot" for temperature is between 40°F and 55°F. You want a spot that is consistently cool but never reaches the freezing mark.
- Unheated Basements: Usually the best option in older homes. They tend to stay cool and have a touch of natural humidity.
- Crawl Spaces: These often provide the perfect temperature range, though they can sometimes be a bit too damp.
- Attached Garages: This can work well, but be cautious. Garages can fluctuate wildly in temperature. If you use a garage, place your storage boxes on a shelf rather than the cold concrete floor, and move them toward the inner wall (the wall shared with the house) for extra warmth.
- Root Cellars: The gold standard for bulb storage. They provide the stable, cool environment that mimics the rhizomes' natural dormancy period.
Avoid storing cannas near a furnace, water heater, or any heat vents. Excessive heat will either dry the rhizomes out completely or trick them into thinking it is spring, causing them to sprout prematurely in the dark.
Winter Maintenance and Monitoring
Storing your canna lilies isn't a "set it and forget it" task. To ensure a high success rate, it is a good idea to check on your boxes once a month throughout the winter. This only takes a few minutes but can save your entire collection. Longfield Gardens backs its plants with a 100% Quality Guarantee.
When you check them, look for two things: rot and shriveling. If you see a rhizome that has turned soft or fuzzy with mold, remove it immediately and throw it away. This prevents the rot from spreading to the healthy bulbs nearby. If the rhizomes feel very light and look wrinkled or shriveled, they are getting too dry. Use a spray bottle to lightly mist the packing medium with water. You don't want to soak it—just add enough moisture to stop the dehydration.
Key Takeaway: A quick monthly check for firmness and health ensures that a small problem with one bulb doesn't affect the whole batch.
Storing Container-Grown Cannas
If you grow your cannas in large pots or decorative containers, you have a convenient shortcut. Instead of digging the rhizomes out, you can store the entire pot. After the first frost kills the foliage, cut the stems down to the soil line as usual. Move the entire container to a cool, dark, frost-free location like a basement or garage. For a medium-height option you can grow in a pot, Canna Medium Banana Punch is a good one to browse.
Stop watering the pot entirely. The soil will dry out, and the rhizomes will go dormant right where they are. In the spring, you can move the pot back outside, start watering again, and wait for the new shoots to emerge. This is a great time-saver, though every couple of years you should still tip the pot out to divide the rhizomes so they don't become too crowded.
Transitioning to Spring
As the days get longer and the ground begins to warm, your stored cannas will start to wake up. You may see small white or pink "pips" (new sprouts) beginning to push through the packing medium. This is your signal that the growing season is near!
Wait until the danger of frost has passed in your area before planting them back in the garden. For an earlier start, you can "pot up" your rhizomes indoors about 4 to 6 weeks before the last frost date. If you're planning to replace or add to your collection, our Shipping Information page explains timing by zone. Place them in a sunny window or under grow lights to give them a head start. By the time the weather is consistently warm, you will have established plants ready to leap into growth.
At Longfield Gardens, we believe that the effort spent on winter storage is well worth the reward. There is a special kind of satisfaction that comes from seeing a massive, flowering canna and knowing it started as a small rhizome you carefully tucked away for the winter. It connects you to the cycle of the seasons and makes the arrival of spring even more exciting.
Summary of Canna Storage Steps
Storing canna lilies is a simple cycle of timing, cleaning, and cooling. By getting these few basics right, you can enjoy these tropical favorites year after year.
- Wait for the Signal: Let the first frost turn the leaves brown before you start digging.
- Be Gentle: Lift the whole clump and rinse away the soil without scrubbing the skins.
- Cure for Strength: Allow a week of air-drying to toughen the outer skins.
- Pick the Right Bedding: Use barely damp peat moss or dry wood shavings in a breathable container.
- Check and Balance: Monitor your storage boxes monthly for moisture levels and health.
Overwintering your own cannas is a great way to build a massive garden display over time. Each year your collection grows, giving you more plants to fill your beds or share with friends, including dramatic choices like Canna Tall Tropicanna Black.
For the best results, always start with high-quality plants that have had a full season of sun and nutrients. We provide premium rhizomes that are ready to perform, ensuring you have a strong foundation for your garden. If you are ready to expand your collection or try a new color this year, feel free to browse our selection at Canna Short Pink Magic. Happy gardening!
FAQ
Can I store canna bulbs in a refrigerator?
It is generally not recommended to store canna rhizomes in a refrigerator. Most home refrigerators are kept between 35°F and 38°F, which is slightly too cold for tropical cannas and may lead to tissue damage. Additionally, the low humidity and lack of airflow in a fridge can cause the rhizomes to rot or dry out prematurely.
Do I have to wash the soil off the rhizomes before storing?
While you don't have to wash them perfectly clean, removing the bulk of the soil is highly beneficial. Soil can harbor fungi and pests that may cause rot during the winter months. Rinsing the rhizomes also makes it much easier to see the "eyes" and identify any damaged areas that should be trimmed away before packing.
What happens if I dig my cannas before the first frost?
Digging early won't necessarily kill the plant, but it may result in smaller blooms the following year. The period between late summer and the first frost is when the plant is most active in storing carbohydrates in the rhizome. Waiting for the frost ensures the rhizome is as "fat" and energy-rich as possible before it goes dormant.
Should I use plastic bags for storing my canna lilies?
You can use plastic bags if you take precautions, but they are riskier than breathable containers. If you use plastic, make sure the bag is not sealed shut and poke several large air holes around the sides. This allows moisture to escape so the rhizomes do not "sweat," which is a leading cause of mold and rot during storage.