Table of Contents
- Introduction
- Understanding Canna Rhizomes
- Do You Need to Dig Your Cannas?
- When to Dig Canna Bulbs
- Preparing the Plants for Digging
- How to Dig Canna Rhizomes Safely
- The Curing Process
- To Divide or Not to Divide?
- Choosing the Right Storage Medium
- The Ideal Storage Environment
- Winter Maintenance and Monitoring
- Storing Container-Grown Cannas
- Getting a Head Start in Spring
- Why We Love Cannas
- Summary of Canna Storage Steps
- FAQ
Introduction
Watching the bold, tropical foliage of canna lilies reach for the summer sky is one of the most rewarding experiences in the garden. These plants bring an effortless vacation vibe to any backyard, with their vibrant blooms and lush leaves that last until the first hints of autumn. At Longfield Gardens, we believe that the beauty of summer doesn’t have to end when the temperature drops.
Storing your canna bulbs is a simple and satisfying way to ensure your favorite varieties return year after year. While they are tropical by nature, these plants are remarkably resilient if you give them a little care during the colder months. This guide is designed for home gardeners who want to keep their landscape looking beautiful without starting from scratch every spring.
Learning how to store canna bulbs properly will save you time and money while allowing your garden to grow more impressive with each passing season. By following a few straightforward steps, you can successfully overwinter your cannas and prepare them for a spectacular spring debut.
Understanding Canna Rhizomes
Before we dive into the storage process, it is helpful to know what we are actually working with. While most gardeners use the term "bulbs," cannas actually grow from rhizomes. A rhizome is a fleshy, horizontal underground stem that stores energy for the plant.
When you look at a canna rhizome, you will see small bumps known as "eyes." These are the growth points where next year's stems and leaves will emerge. Because these structures are full of moisture and nutrients, they are sensitive to freezing temperatures. In many parts of the United States, the ground gets cold enough to damage these energy stores, which is why we bring them indoors for the winter.
Do You Need to Dig Your Cannas?
Whether or not you need to dig and store your canna bulbs depends primarily on your local climate. Gardeners in warmer regions can often leave their plants in the ground year-round, while those in cooler areas will need to provide a cozy spot indoors.
Identifying Your Garden Zone
In the United States, we use USDA Hardiness Zones to determine which plants can survive the winter outdoors. Cannas are generally considered hardy in zones 8 through 11. In these areas, the soil rarely freezes deep enough to harm the rhizomes. If you live in zone 8 or warmer, you can usually leave your cannas in the ground. Simply cut the foliage back after it turns brown and apply a thick layer of mulch, such as straw or shredded leaves, to provide extra insulation.
When Storage is Necessary
If you live in zone 7, your cannas are in a "swing" zone. Many gardeners in zone 7 find success leaving them in the ground with heavy mulching, especially if the plants are located near a warm south-facing wall. However, if a particularly cold winter is predicted, digging them up is the safest bet.
For those in zones 3 through 6, digging and storing is a necessary part of the autumn routine. Because the ground freezes solid in these regions, the moisture inside the rhizome would expand and turn to mush if left outside. Fortunately, the process of bringing them in is very easy and takes only a short amount of time.
When to Dig Canna Bulbs
Timing is everything when it comes to preparing cannas for storage. You want to give the plant as much time as possible to store energy, but you must act before the ground itself freezes.
Waiting for the First Frost
The best signal to start digging is the first light frost. You will notice the lush green or bronze leaves turn black or brown almost overnight after a cold snap. This is perfectly normal and actually helpful. This "killing frost" tells the plant that it is time to go dormant.
When the foliage dies back, the plant stops sending energy upward and focuses entirely on the rhizome below. If you can, wait until this frost happens before you get your shovel. If you live in an area where the transition from fall to winter is very fast, keep an eye on the forecast and aim to dig before the first hard freeze (when the ground begins to crust over).
Nature’s Dormancy Signal
Waiting for the foliage to die back naturally ensures that the rhizome is as "recharged" as possible. Think of the leaves as solar panels that have been collecting energy all summer long. By letting them stay until the frost hits, you are maximizing the blooms you will see next year.
Key Takeaway: The ideal time to dig cannas is immediately after the first frost has blackened the foliage, but before the ground freezes solid.
Preparing the Plants for Digging
Once the frost has done its work, it is time to prepare the plants. Having a clear workspace makes the digging process much easier and keeps your garden tidy.
Cutting Back the Foliage
Start by cutting the stems down. Use a sharp pair of garden shears or a lopper to cut the stalks about 2 to 4 inches above the soil line. Leaving a small "handle" of the stem makes it easier to locate the center of the clump and provides something to hold onto when you are lifting the rhizomes out of the dirt.
Dispose of the blackened foliage in your compost pile or green waste bin. Clearing away the old leaves allows you to see exactly where you need to dig and prevents the dead material from getting in your way.
Gathering Your Tools
To dig canna bulbs safely, you will need a few basic tools:
- A sturdy garden spade or a digging fork.
- A pair of garden gloves to protect your hands.
- A garden hose with a spray nozzle (optional).
- A wheelbarrow or garden cart to transport the heavy clumps.
How to Dig Canna Rhizomes Safely
The goal during the digging process is to lift the rhizomes without cutting or bruising them. While cannas are tough, a "wound" on the rhizome can be an entry point for moisture or unwanted pests during the winter.
Loosening the Soil
Cannas grow outward from the center, so the root mass can be much wider than the original plant you put in the ground. Start your shovel about 6 to 12 inches away from the base of the stems. Push the spade straight down into the soil all the way around the clump. This circular path severs the smaller feeder roots while leaving the main rhizomes intact.
Lifting the Clump
Once you have loosened the soil in a circle, gently pry the clump upward. If the clump feels stuck, move your spade a bit further out and try again. It is often helpful to work with a partner for very large clumps, as they can be surprisingly heavy.
Lift the entire mass out of the ground and set it on the grass or in your wheelbarrow. At this stage, the rhizomes will likely be covered in a fair amount of garden soil.
Cleaning the Rhizomes
You have two choices when it comes to cleaning: the "shake" method or the "rinse" method.
- The Shake Method: If your soil is sandy or dry, you can simply shake the clump or rub the dirt off with your gloved hands. This keeps the rhizome dry, which can be helpful if you live in a very humid climate.
- The Rinse Method: If you have heavy clay soil that clings to the roots, use a garden hose to gently wash the dirt away. This allows you to see the "eyes" clearly and check the health of the rhizome. If you use water, it is very important to let the rhizomes dry thoroughly before moving them to storage.
The Curing Process
Curing is a fancy gardening term for letting the rhizomes air-dry before they are packed away. This is one of the most important steps in learning how to store canna bulbs successfully.
Why Curing Matters
When a rhizome is first dug up, its "skin" is very thin and tender. Curing allows the outer surface to toughen up, creating a protective barrier. It also ensures that any excess moisture on the surface evaporates, which is the best way to prevent issues during the winter.
How to Cure Your Cannas
Place your cleaned rhizomes in a well-ventilated area that is protected from rain and direct frost. A garage, a covered porch, or a shed works perfectly. Spread them out in a single layer on a piece of cardboard or a newspaper.
Let the rhizomes sit for 2 to 7 days. You will notice the outer skin starts to look a bit like a potato skin—dull and dry to the touch. Once they feel dry and the remaining bits of soil fall off easily, they are ready for their winter home.
To Divide or Not to Divide?
One of the best things about growing cannas is that they multiply! A single rhizome planted in May can turn into a large clump by October. You can choose to store the entire clump as one piece, or you can divide it into smaller sections.
Benefits of Dividing in Fall
Some gardeners prefer to divide their cannas in the fall because the rhizomes are already out of the ground and the "eyes" are easy to see. Dividing now also saves space in your storage containers.
To divide, use a sharp, clean knife to cut the rhizome into sections. Each section should have at least two or three "eyes" (those little bumps where growth happens). If you make any cuts, let those pieces cure for an extra day or two so the "wound" can callous over before storage.
Keeping It Simple
If you are busy or have plenty of storage space, there is no harm in storing the whole clump. You can always divide the plants in the spring right before you put them back in the garden. This is often the easier path for beginners.
Next Steps for Success:
- Cut stalks to 3 inches after the first frost.
- Dig 12 inches away from the stem to avoid damage.
- Cure in a dry, shaded area for several days.
- Label your varieties now so you don't forget which is which!
Choosing the Right Storage Medium
You cannot simply toss canna rhizomes into a plastic bin and forget about them. They need a storage medium that regulates moisture—something that keeps them from drying out completely while also preventing them from staying too wet.
Popular Storage Materials
There are several great options for packing your cannas. We suggest using what you have on hand:
- Peat Moss: This is the most common choice. It is naturally sterile and holds just a tiny bit of moisture.
- Vermiculite or Perlite: These lightweight minerals provide excellent aeration.
- Wood Shavings or Sawdust: Often used for animal bedding, these are inexpensive and work well.
- Newspaper: You can wrap individual rhizomes in several layers of dry newspaper.
- Potting Soil: Some gardeners use dry, fresh potting soil to "bury" the rhizomes in a bin.
Containers for Storage
Your container should allow for a little bit of air circulation. Plastic totes are popular, but it is a good idea to leave the lid slightly cracked or drill a few small holes in the sides. Cardboard boxes, wooden crates, and paper bags also work very well because they "breathe" naturally.
The Ideal Storage Environment
Where you keep your containers is just as important as how you pack them. The goal is to keep the rhizomes in a "Goldilocks" zone—not too cold, not too hot, and not too bright.
Temperature Requirements
The ideal temperature for storing canna bulbs is between 40°F and 55°F. This is cold enough to keep the plants in a state of deep sleep (dormancy) but warm enough that they won't freeze.
- Unheated Basements: Usually the best spot in most homes.
- Crawl Spaces: Often maintain a consistent, cool temperature.
- Cool Closets: An interior closet in a mudroom or hallway can work if your house stays relatively cool.
- Avoid Garages: Unless your garage is insulated and attached to the house, it may get too cold during a deep freeze.
Darkness is Key
Cannas need darkness to stay dormant. If they are exposed to light and warmth, they might think spring has arrived early and start to sprout in the box. Keep your storage containers in a dark corner to ensure they rest peacefully until it is time to grow.
Winter Maintenance and Monitoring
Storing canna bulbs is not quite a "set it and forget it" task. A quick check once a month will ensure that your plants stay healthy all winter long.
Checking for Moisture Balance
Open your containers once a month to see how the rhizomes are doing.
- If they look shriveled: They might be getting too dry. Use a spray bottle to lightly mist the storage medium (the peat moss or shavings) with a little water. You don't want it wet, just barely damp.
- If they feel soft: This is a sign of too much moisture. Remove any soft pieces immediately so the issue doesn't spread to the healthy rhizomes. Leave the lid off the container for a few days to let excess moisture evaporate.
By spending five minutes a month checking your boxes, you can catch minor issues before they become problems. This proactive approach is one of the "easy wins" we recommend to ensure gardening remains a joy.
Storing Container-Grown Cannas
If you grow your cannas in large pots on your patio, the storage process can be even simpler. You don't necessarily have to dig them out of the soil.
The "Pot-in-Pot" Method
After the frost hits and you have cut back the foliage, you can simply move the entire pot into a frost-free area like a basement or a cool garage. Stop watering the soil entirely. The soil in the pot acts as the storage medium. In the spring, you can pull the rhizomes out to divide them, refresh the soil, and move the pot back outside.
For more on growing container-grown cannas, this method is a great time-saver, though it does require more physical space than storing loose rhizomes in a box.
Getting a Head Start in Spring
As winter fades and the days grow longer, you will start to look forward to getting back into the garden. One of the perks of storing your own cannas is that you can "wake them up" early to get a jump on the growing season.
Waking Up the Rhizomes
About 4 to 6 weeks before the last expected frost date in your area, you can bring your storage containers into a warmer, brighter room. If you divided them in the fall, you can pot them up in individual containers with some moist potting soil.
For step-by-step planting guidance, see How to Plant Canna Lily Bulbs. Place the pots near a sunny window or under a simple grow light. Once they feel the warmth and see the light, those "eyes" will begin to sprout. By the time the weather is warm enough to plant them outside, you will already have established plants that are ready to take off.
Moving Back Outdoors
Wait until the soil has warmed up and there is no danger of frost before transplanting your cannas into the garden. Just like we matched the plant to the right spot in the fall, we want to give it the best start in the spring. Choose a sunny location with well-draining soil, and your stored cannas will reward you with a spectacular show of color.
"The secret to a lush, tropical garden year after year is simply understanding the natural rhythm of the plants. Bringing cannas indoors for the winter isn't a chore; it's an investment in next summer's beauty."
Why We Love Cannas
Cannas are among the most versatile plants you can grow. From the towering 'Red King Humbert' to the beautifully striped foliage of 'Pretoria,' there is a variety for every garden style. For a broader overview, see All About Cannas. At Longfield Gardens, we take pride in providing high-quality rhizomes that are ready to perform.
When you store your own bulbs, you are participating in a timeless gardening tradition. You get to see the lifecycle of the plant up close, from the first sprout in spring to the dormant rhizome in winter. It builds a connection to your landscape that makes every bloom feel even more special.
Summary of Canna Storage Steps
To wrap everything up, here is a quick checklist to keep you on track as you learn how to store canna bulbs:
- Wait for the frost: Let the first cold snap turn the leaves brown.
- Cut and Dig: Trim the stems to 3 inches and lift the clumps gently with a spade.
- Clean and Cure: Remove excess soil and let the rhizomes dry in a cool, shaded area for a few days.
- Pack it up: Use peat moss, newspaper, or wood shavings in a breathable container.
- Find the "Goldilocks" spot: Store in a dark, cool place (40-55°F).
- Check monthly: Ensure they aren't too dry or too damp.
Gardening is all about these simple cycles. By taking these easy steps today, you are setting the stage for a vibrant, tropical paradise in your yard next year. If you find yourself with more canna bulbs than you have space for after dividing, they make wonderful gifts for neighbors and friends!
For more tips on choosing the right plants for your zone or planning your next flower bed, we invite you to explore our other guides. If you’re placing an order, our Shipping Information page explains timing and delivery, and Longfield Gardens is here to help you grow a more beautiful world, one bulb at a time.
FAQ
Can I store canna bulbs in the refrigerator?
While a refrigerator is cool and dark, it is generally too cold for canna rhizomes, as most fridges are set near 35°F. Additionally, fruits and vegetables in the fridge release ethylene gas, which can interfere with the dormancy of the rhizomes. A cool basement or crawl space is a much better environment.
Do I need to wash the dirt off the canna rhizomes before storing?
It isn't strictly necessary to wash them, and in some cases, leaving a bit of dry soil can actually help protect the rhizome. However, washing them makes it much easier to inspect for pests or damage and allows you to see where to make cuts if you are dividing them. If you do wash them, ensure they dry completely before packing.
What happens if I forget to dig my cannas before a hard freeze?
If the ground freezes solid before you dig, the rhizomes may be damaged. However, the soil usually takes longer to freeze than the air. If you've had a few cold nights but the ground is still soft enough to dig, your cannas are likely fine. Dig them as soon as possible and check that the rhizomes are still firm and not mushy.
Should I use plastic bags to store my canna bulbs?
You can use plastic bags, but you must add several air holes to prevent moisture buildup and rot. A better option is a paper bag or a cardboard box filled with a dry medium like peat moss. These materials allow the rhizomes to "breathe," which significantly reduces the risk of mold during the winter months. If product quality or arrival condition is a concern, our 100% Quality Guarantee explains how Longfield Gardens stands behind its bulbs and plants.