Table of Contents
- Introduction
- Understanding Canna Lily Dormancy
- Timing the Harvest
- Preparing to Dig Your Cannas
- Cleaning and Inspecting the Rhizomes
- The Importance of Curing
- Choosing the Right Storage Medium
- Packing Your Cannas for the Winter
- Finding the Ideal Storage Location
- Monitoring Your Cannas Over Winter
- Storing Potted Canna Lilies
- Transitioning Back to the Garden
- Celebrating Your Gardening Success
- FAQ
Introduction
There is nothing quite like the tropical flair that canna lilies bring to a summer garden. Their bold, oversized leaves and vibrant, torch-like flowers create a lush atmosphere that lasts from midsummer right through the first touch of autumn. If you have fallen in love with these architectural beauties, you will be happy to know that you can keep them for many years.
At Longfield Gardens, we believe that preserving your favorite plants should be a rewarding part of the gardening cycle, and our Cannas Bulbs for Sale selection makes it easy to start with fresh rhizomes for next season. Storing canna lilies—technically known as rhizomes—is an easy way to save money and ensure your garden is even more spectacular next year. This guide will walk you through the simple process of digging, curing, and storing your cannas so they stay healthy and ready for spring.
We have designed this tutorial for home gardeners who want clear, actionable steps for winter care. Whether you are a beginner or a seasoned grower, these techniques will help you protect your investment. For a broader overview of the plant, see All About Cannas. By following a few basic principles, you can look forward to bigger, better blooms every single season.
Understanding Canna Lily Dormancy
Canna lilies are tropical plants that thrive in heat and humidity. In warmer climates, specifically USDA hardiness zones 8 through 10, they can often remain in the ground year-round. If you're not sure where you live, the Hardiness Zone Map is a helpful check. However, for gardeners in zones 7 and colder, the freezing temperatures of winter will damage the fleshy rhizomes if they are left in the soil.
The goal of winter storage is to guide the plant into a period of rest, or dormancy. This process allows the plant to stop active growth and preserve its energy inside the rhizome. When the weather turns cold, the plant naturally begins to shut down. By timing your harvest correctly, you work with the plant’s internal clock.
Successful storage starts with recognizing the signs that the plant is ready for its winter nap. You do not need to be a botanist to get this right. The changes in the plant’s appearance and the shift in autumn weather provide all the cues you need to begin the process.
Timing the Harvest
The most common question gardeners ask is when exactly they should begin digging up their cannas. While it might be tempting to tidy up the garden as soon as the first yellow leaf appears, patience is a virtue here. The plant uses the late summer and early fall to store up energy for next year’s growth, and the Tall Cannas collection is a good place to compare the dramatic, upright varieties that make the strongest statement.
Wait for the first light frost to hit your area. A light frost will usually turn the canna’s lush green or bronze foliage to a dark brown or black. This may look a bit sad at first, but it is actually a positive sign. The frost signals to the rhizome that it is time to stop growing and go dormant.
If you live in an area where a hard freeze (where the ground actually freezes deep down) happens quickly, you should aim to dig the rhizomes shortly after that first light frost kills the leaves. You want the plant to be dormant, but you do not want the rhizomes themselves to freeze. A frozen rhizome will turn to mush and will not survive the winter.
Key Takeaway: Nature provides the best signal for digging. Wait for a light frost to blacken the foliage, as this tells the plant to move its energy down into the rhizome for winter.
Preparing to Dig Your Cannas
Before you head out to the garden, gather a few basic tools. You will need a sturdy garden fork or a sharp spade. A garden fork is often preferred because it is less likely to slice through the rhizomes, but a spade works well if you are careful. You may also want a pair of garden gloves and a set of bypass pruners or sharp garden scissors. For gardeners who want a smaller footprint next season, Short Cannas are an easy group to compare.
Start by cutting back the foliage. Use your pruners to trim the stalks down to about 4 to 6 inches above the soil line. Removing the bulky leaves makes it much easier to see where the base of the plant is and gives you a "handle" to grab later. Do not worry about the height of the cut being exact; the main goal is to clear the workspace.
Clear away any mulch or debris from around the base of the plants. This gives you a clear view of the soil and helps you identify the edges of the root mass. Canna rhizomes can grow quite large over a single summer, so they might be wider than you expect.
Digging with Care
When you are ready to dig, start several inches away from the base of the stalks. A good rule of thumb is to begin about 10 to 12 inches out from the center of the clump. This helps ensure you do not accidentally spear the rhizomes with your tool.
- Insert your fork or spade deeply into the soil at a slight angle, pointing toward the plant.
- Gently rock the tool back and forth to loosen the soil.
- Move around the entire circumference of the plant, loosening the earth as you go.
- Once the clump feels loose, use the tool to lever the entire mass upward.
- Lift the clump out of the ground by the base of the remaining stalks.
Cleaning and Inspecting the Rhizomes
Once the cannas are out of the ground, you will likely see a large mass of soil clinging to the roots. Shake the clump gently to remove the heaviest pieces of dirt. You can also use your hands to brush away loose soil.
Some gardeners prefer to rinse their rhizomes with a garden hose to get them completely clean. This can make it easier to see the "eyes" (growth points) and check for any signs of damage or disease. If you choose to wash them, be very gentle. The skin of a freshly dug canna rhizome is thin and easily bruised. Avoid scrubbing them with a brush, as any wounds can become entry points for rot during storage.
The Inspection Phase
Take a moment to look closely at your harvest. A healthy canna rhizome should feel firm and heavy for its size. If you find any parts that are soft, mushy, or smell foul, trim those sections away with a clean, sharp knife. If you want a compact, container-friendly follow-up planting, Canna Short Orange Magic is a good example to keep in mind.
You may also notice that your single plant from the spring has grown into a large, multi-sectioned clump. You can choose to leave these clumps whole for the winter or break them into smaller pieces. If you divide them now, ensure each piece has at least one or two "eyes." If you make any cuts, it can be helpful to let the rhizomes sit in a dry spot for a few hours to allow the cut surface to "callous" or dry over before the next step.
The Importance of Curing
Curing is perhaps the most overlooked step in storing canna lily bulbs, but it is essential for long-term success. Curing is simply a fancy word for letting the rhizomes air-dry for a short period. This process allows the outer skin to toughen up, creating a natural barrier against moisture loss and rot.
To cure your cannas, find a dry, well-ventilated area that stays out of direct sunlight. A garage, a garden shed, or even a covered porch works perfectly. Spread the rhizomes out in a single layer on a piece of cardboard, a tarp, or a wire rack.
How long should you cure them? Usually, about 4 to 7 days is sufficient. You are looking for the exterior of the rhizome to feel dry to the touch and for any remaining soil to turn dusty. If the weather is particularly humid, you might need a few extra days. The goal is to remove excess surface moisture without letting the interior of the rhizome dry out completely.
Key Takeaway: Curing for 4–7 days in a dry, shaded spot is the secret to preventing rot. This simple step toughens the skin and prepares the plant for months of storage.
Choosing the Right Storage Medium
You cannot simply toss canna rhizomes into a plastic bin and hope for the best. To survive the winter, they need a environment that is "just right"—not too wet and not too dry. This is where a storage medium comes in. The medium helps regulate the humidity around the rhizomes, preventing them from shriveling up or rotting.
There are several excellent options for storage media, most of which are readily available at your local garden center. If you like the idea of mixing color and size in one order, Assorted Cannas can be a useful place to compare options for next season:
- Peat Moss: This is the most popular choice. It holds a tiny bit of moisture but stays fluffy enough to allow air to circulate.
- Vermiculite or Perlite: These lightweight minerals are excellent for moisture control.
- Wood Shavings: Often sold as pet bedding, these are inexpensive and provide great insulation.
- Newspaper: Wrapping individual rhizomes in dry newspaper is a classic, low-cost method that works surprisingly well.
- Dry Sand: While heavy, sand provides a very stable environment for the rhizomes.
At Longfield Gardens, we often find that a mix of slightly damp peat moss or wood shavings provides the best balance for most home gardeners. The medium should feel like a wrung-out sponge—barely damp, but not wet.
Packing Your Cannas for the Winter
Once your cannas are cured and you have chosen your medium, it is time to pack them away. You want a container that allows for a small amount of air exchange. Cardboard boxes, paper bags, or plastic bins with holes drilled in the sides are all excellent choices. Avoid airtight containers, as they trap moisture and almost always lead to mold.
The Layering Method
- Place a 2-to-3-inch layer of your chosen medium at the bottom of the container.
- Arrange the rhizomes in a single layer on top of the medium. Make sure they are not touching each other. This prevents a single spot of rot from spreading to the whole batch.
- Cover the layer with more medium until the rhizomes are completely hidden.
- If your container is deep enough, you can add a second layer of rhizomes and cover them again.
- Finish with a final layer of medium on top.
If you are using the newspaper method, simply wrap each rhizome like a small burrito and stack them loosely in a cardboard box. This method is particularly good if you have a limited amount of space, as it keeps the rhizomes separated and provides a buffer against temperature changes. For a balanced, mid-height display next season, Medium Cannas are worth a look.
Finding the Ideal Storage Location
Where you put your container is just as important as how you pack it. Canna lilies need a spot that is cool and dark. The ideal temperature range is between 45°F and 55°F (7°C to 13°C).
If the temperature drops below 40°F, you risk the rhizomes freezing. If the temperature rises above 60°F, the cannas might think it is spring and start to sprout prematurely. Sprouting in the dark consumes the energy stored in the rhizome, which can lead to a weaker plant once it is finally moved outside.
Common successful storage spots include:
- An unheated basement or crawlspace.
- An attached garage that stays above freezing.
- A cool closet in a mudroom.
- A root cellar.
Keep the containers off the floor if possible, especially on concrete floors which can pull heat away or become damp. Placing the box on a wooden pallet or a shelf is a smart move.
Monitoring Your Cannas Over Winter
Storing canna lilies is not a "set it and forget it" task. To ensure the highest survival rate, you should check on your rhizomes about once a month. This only takes a few minutes but can save your entire collection.
Open the containers and feel a few of the rhizomes. They should still feel firm. If you notice any of the following, take action immediately:
- Signs of Rot: If a rhizome feels soft or has visible mold, remove it immediately. If the rot is only on a small tip, you can cut it off and let the healthy part dry before putting it back, but usually, it is safest to discard the affected piece so it doesn't infect the others.
- Signs of Shriveling: If the rhizomes look very wrinkled or feel lightweight, they are getting too dry. Use a spray bottle to lightly mist the storage medium. You don't want to soak it—just add a tiny bit of humidity back into the air.
- Premature Sprouting: If you see pale green or white shoots starting to grow, your storage spot is likely too warm. Try to move the containers to a slightly cooler location.
Storing Potted Canna Lilies
If you grow your cannas in large pots or containers, you have an even easier option. You do not necessarily need to dig them up at all. For more ideas on pot sizes, drainage, and warm-season container growing, see How to Grow Summer Bulbs in Containers.
When the frost hits and the leaves turn brown, cut the stalks down to the soil level as you would with garden-planted cannas. Move the entire pot—soil and all—into a cool, frost-free location like a basement or garage. Stop watering the pot completely. The soil will dry out, and the rhizomes will go dormant right where they are.
In the spring, you can pull the pot back out into the sun, give it a good soak, and the plants will usually begin to grow again. Keep in mind that cannas grow very quickly, so after a year or two in a pot, they will likely become "root-bound." Every couple of seasons, it is a good idea to tip the pot out, divide the rhizomes, and replant them with fresh soil to keep them vigorous.
What to do next:
- Check your local weather forecast for the first frost date.
- Prepare your storage medium (peat moss or wood shavings) in advance.
- Clear a space in your basement or garage for the storage boxes.
- Label your boxes by variety or color so you know what is what in the spring!
Transitioning Back to the Garden
When the days begin to lengthen and the threat of frost passes in the spring, it is time to wake up your cannas. This is an exciting time for any gardener! You will likely see small "eyes" or even tiny shoots beginning to emerge from the rhizomes. If you want a step-by-step companion for spring planting, How to Plant Canna Lily Bulbs is a helpful next read.
Before planting them directly in the garden, many gardeners like to give their cannas a head start. You can plant the rhizomes in pots indoors about 4 to 6 weeks before the last frost date. Place them in a warm, sunny window and water them sparingly until you see growth. This "jump start" ensures you get flowers much earlier in the summer.
If you prefer to plant directly into the ground, wait until the soil has warmed up to at least 60°F. Cannas love warm soil and will sit idly if the ground is too cold and wet. When you do plant, place the rhizomes about 4 inches deep with the eyes pointing up. For more detail on depth, read How Far Down Do You Plant Canna Bulbs? Give them plenty of sun and consistent water, and you will soon see those familiar tropical leaves stretching toward the sky.
Celebrating Your Gardening Success
Preserving canna lilies is a wonderful way to connect with the rhythm of the seasons. There is a deep satisfaction in seeing a plant you cared for last year emerge from the soil once again, bigger and stronger than before. It turns gardening from a series of one-off purchases into a continuous journey of growth and discovery.
By following these simple steps—digging after frost, curing thoroughly, and storing in a cool, dark place—you are setting yourself up for a beautiful landscape year after year. We at Longfield Gardens are honored to be a part of your gardening story. We believe that everyone can have a stunning garden, and sometimes the best way to achieve that is simply by protecting the treasures you already have.
We stand behind the quality of our plants and the success of our fellow gardeners. With a little bit of care this autumn, your cannas will be ready to put on a spectacular show once the warm weather returns. Happy gardening, and enjoy the peace of the winter season!
FAQ
Do I really have to wait for a frost to dig up my canna bulbs?
While it is not strictly mandatory, waiting for a light frost is highly recommended. The frost serves as a natural signal to the plant to move its energy into the rhizome and enter dormancy. If you dig them up while they are still actively growing, the rhizomes may not have as much stored energy to last through the winter.
Can I store my cannas 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 a bit too cold for tropical cannas and may cause damage. Additionally, refrigerators are very dry and often contain ripening fruits that release ethylene gas, which can interfere with the health of the rhizomes.
What should I do if my cannas start to sprout in February?
If you see sprouts early in the year, it is a sign that your storage area is too warm. Move the container to a cooler spot if possible. If the sprouts are small, you can usually leave them alone; just be careful not to break them when you eventually plant. If they are growing rapidly, you may need to pot them up indoors to keep them healthy until it is warm enough to go outside.
How do I know if a canna rhizome is dead and should be thrown away?
A dead or non-viable rhizome will usually feel very light and hollow (completely dried out) or very soft and mushy (rotted). If you squeeze the rhizome and it gives way easily or oozes liquid, it is gone. Healthy rhizomes should always feel heavy for their size and firm to the touch, similar to a fresh ginger root or a potato. If you ever need help with a damaged order, see our 100% Quality Guarantee.