Best Way to Store Canna Bulbs for Winter

Table of Contents

1. Introduction
2. Understanding Canna Hardiness
3. When to Dig Your Canna Rhizomes
4. Preparing the Plants for Lifting
5. How to Lift Canna Rhizomes Safely
6. Cleaning and Curing the Rhizomes
7. To Divide or Not to Divide?
8. Choosing the Best Storage Medium
9. Packing Your Cannas for the Winter
10. Finding the Perfect Storage Location
11. Checking Your Rhizomes Mid-Winter
12. What to Do Next: A Storage Summary
13. Moving Cannas from Containers
14. Preparing for Spring Replanting
15. Conclusion
16. FAQ

Introduction

Canna lilies bring a bold, tropical energy to the garden that few other plants can match.

Their oversized, paddle-shaped leaves and vibrant, torch-like blooms make any backyard feel like a private island getaway. At Longfield Gardens, we love how these fast-growing plants transform a landscape in just one season. Whether you grow them for their sunset-colored flowers or their dramatic, variegated foliage, they are among the most rewarding plants for a sunny border or a large patio container.

Because cannas are tropical plants, they thrive in the heat of summer but cannot survive freezing temperatures. In most parts of the country, this means the "bulbs"—which are actually called rhizomes—need a little help to make it through the winter. This article will teach you the best way to store canna bulbs for winter so you can enjoy these stunning plants year after year.

Our goal is to make the overwintering process feel like a simple, satisfying part of your gardening routine. By following a few basic steps, you can keep your plants healthy and dormant until the warm weather returns. With the right care, your cannas will be ready to sprout again as soon as the spring soil warms up.

Understanding Canna Hardiness

Before you grab your garden fork, it helps to know if you actually need to dig your cannas up. Gardening success often starts with knowing your local conditions and how they interact with your plants' needs. Cannas are generally hardy in USDA zones 7 through 10; you can check the USDA hardiness zone map for your own garden.

If you live in Zone 8, 9, or 10, you can typically leave your cannas in the ground all year. In Zone 7, many gardeners choose to leave them in the soil but apply a thick layer of mulch, such as straw or shredded leaves, to provide an extra blanket of protection. However, if you live in Zone 6 or colder, the winter frost will penetrate the soil and turn the rhizomes into mush. In these areas, lifting and storing them is the best way to ensure they return.

The exact timing for this process depends on your local weather. You do not need to worry about the first light frost of autumn. In fact, that first touch of cold is actually a helpful signal for the plant. We find that waiting for the right environmental cues makes the transition into dormancy much smoother for the plant.

When to Dig Your Canna Rhizomes

The best time to dig up your cannas is shortly after the first "killing frost." This is a frost that is cold enough to turn the lush green or bronze foliage into a dark, wilted brown. While it might look a bit sad to see your tropical beauties lose their luster, this change is actually beneficial.

When the foliage dies back, the plant stops sending energy to the leaves and begins to store all its resources in the rhizome. This helps the bulb stay strong throughout the long winter months. You don't have to rush out the very next morning, but you should aim to get them out of the ground before the soil itself begins to freeze hard.

A good rule of thumb is to wait for the leaves to turn black or brown, then plan your "digging day" within the next week or two. If you have a particularly large collection of cannas, keep an eye on the long-range forecast. You want to work while the soil is still workable and not a frozen block of ice.

Preparing the Plants for Lifting

Before you start digging, you need to clear away the spent foliage. Use a pair of sharp garden loppers or a sturdy pair of bypass pruners. Cut the stems down so that only about 4 to 6 inches of the stalk remains above the soil line.

Leaving a few inches of the stem serves a practical purpose. It gives you a "handle" to hold onto while you are cleaning the rhizomes, and it helps you keep track of which side is up. More importantly, it keeps the growing points, or "eyes," protected while you handle the plant.

Once the tops are removed, you can clear away any mulch or debris from around the base of the plants. This makes it easier to see exactly where the root mass begins. Cannas are vigorous growers, and a single rhizome planted in the spring can grow into a large, heavy clump by autumn. Being able to see the full footprint of the plant will help you avoid accidental damage during the lifting process.

How to Lift Canna Rhizomes Safely

Lifting cannas is a straightforward task, but it requires a bit of care to avoid slicing into the rhizomes. A rhizome is essentially a thick, fleshy underground stem. If it gets badly cut or bruised, it becomes more susceptible to rot during storage.

We recommend using a garden fork rather than a spade or shovel. The tines of a fork are less likely to shear through the middle of a clump. Start by stepping the fork into the ground about 12 inches away from the base of the stems. Work your way around the entire clump, gently prying upward to loosen the soil and break the tension of the roots.

Once the soil is loose all the way around, use the fork to lift the entire mass out of the ground. Don't be surprised if the clump is much larger and heavier than you expected. Cannas are excellent at multiplying. If the clump is too heavy to lift at once, you can gently use your hands to feel for natural breaking points in the root mass and lift it out in sections.

Key Takeaway: Always dig wider than you think you need to. Starting a foot away from the stem ensures you won't accidentally spear the largest, healthiest parts of the rhizome clump.

Cleaning and Curing the Rhizomes

After the cannas are out of the ground, the next step is to remove the excess soil. You don't need them to be perfectly clean, but removing large clods of dirt makes them easier to store and reduces the risk of carrying soil-borne pests into your storage area.

Gently shake the clump or use your hands to brush away the loose dirt. Avoid using a high-pressure hose to wash them. While it might seem like a good idea to get them clean, introducing too much moisture right before storage can lead to mold and decay. If the soil is very muddy and you must wash them, make sure they dry out completely before you pack them away.

"Curing" is the process of letting the outer skin of the rhizome toughen up. This is a vital step for long-term storage. Place the cleaned rhizomes in a dry, frost-free area like a garage, shed, or covered porch. Keep them out of direct sunlight and away from rain. Let them sit for two to three days. During this time, any remaining soil will dry up and fall off, and the cut ends of the stems will begin to callus over.

To Divide or Not to Divide?

One of the most common questions we hear is whether you should divide your cannas before storing them in the fall or the spring. The answer depends mostly on your available storage space.

Large clumps take up a lot of room. If you are short on space, you can divide them before storing. However, many gardeners prefer to wait until spring. In the spring, the "eyes" (the small bumps where new growth starts) are much easier to see. Waiting also ensures that if a small part of the rhizome dries out over winter, the rest of the clump remains protected.

If you do choose to divide them in the fall, make sure each piece has at least two or three healthy-looking eyes. Use a clean, sharp knife to make the cuts. After dividing, let the pieces cure for an extra day so the new cuts can dry out and form a protective "scab." This simple wait-time is a powerful defense against rot.

Choosing the Best Storage Medium

Canna rhizomes are like goldilocks; they don't want to be too wet, or they will rot, and they don't want to be too dry, or they will shrivel up and die. The best way to store canna bulbs for winter is to pack them in a material that regulates moisture.

Several common household and garden materials work well for this:

• Peat Moss: This is a classic choice because it holds just enough moisture to prevent shriveling but stays airy enough to prevent rot.
• Vermiculite or Perlite: These lightweight minerals provide excellent insulation and aeration.
• Wood Shavings: The kind sold for pet bedding (like cedar or pine) is very effective and affordable.
• Newspaper: If you don't have other materials, wrapping individual rhizomes in several layers of dry newspaper can work well for smaller collections.

Avoid using plastic bags that seal tight. Rhizomes are living things, even when they are dormant, and they need a tiny bit of air circulation. If you use plastic bins, leave the lids slightly ajar or drill a few small holes in the sides to allow gases and excess moisture to escape.

Packing Your Cannas for the Winter

Once your rhizomes are cured and you have chosen your storage medium, it is time to pack them away. We recommend using cardboard boxes, plastic crates, or breathable burlap bags.

Start by placing a 2-inch layer of your chosen medium (like peat moss or shavings) at the bottom of the container. Place the rhizomes on top of the layer, making sure they aren't squeezed too tightly against each other. It is best if they aren't touching, as this prevents rot from spreading if one bulb happens to go bad.

Cover the rhizomes with more of the medium until they are completely buried. If you have a lot of cannas, you can create multiple layers within the same box, just make sure there is plenty of packing material between the layers.

Finally, don't forget to label your boxes! It is very easy to forget which box contains the tall red varieties and which contains the short yellow ones by the time April rolls around. Write the variety name and the flower color on the outside of the box or place a tag inside.

Finding the Perfect Storage Location

The location where you keep your boxes is just as important as the way you pack them. Cannas need a spot that is cool, dark, and dry. The ideal temperature range is between 40°F and 50°F (4°C to 10°C).

If the storage area is too warm, the rhizomes may think it is spring and start to sprout prematurely. If they grow in the dark, the sprouts will be weak, white, and spindly. If the area is too cold and drops below freezing, the rhizomes will die.

Common successful storage spots include:

• An unheated basement or crawl space.
• A cool closet in a mudroom.
• An insulated garage that stays above freezing.
• An attic (if it doesn't get too hot or too cold).

Keep the boxes off the floor if possible, especially if your floor is concrete. Concrete can pull cold and moisture into the box. Placing them on a shelf or a wooden pallet is a safer bet.

Checking Your Rhizomes Mid-Winter

Winter storage isn't a "set it and forget it" task. We recommend checking on your cannas about once a month. This small effort can save your entire collection from a surprise problem.

When you check them, look for two main things: rot and dehydration.

1. Rot: If you see any rhizomes that feel soft, mushy, or have a foul smell, remove them immediately. If only a small part of a large rhizome is soft, you can sometimes cut the bad part away and let the rest dry out, but usually, it is safer to discard the affected piece so the mold doesn't spread to healthy neighbors.
2. Dehydration: If the rhizomes look very wrinkled or feel as light as a piece of cork, they are getting too dry. Use a spray bottle to lightly mist the packing medium with water. You don't want it to be wet—just barely damp to the touch. This will provide enough humidity to plump the rhizomes back up.

Most years, you won't need to do anything at all during these checks, but the peace of mind is worth the five minutes it takes to peek inside the boxes.

What to Do Next: A Storage Summary

To make sure your cannas are ready for a big comeback next year, follow this simple checklist as the season winds down. Taking the right steps now ensures a beautiful garden later.

• Wait for the frost: Let the leaves turn dark before you start the process.
• Cut and lift: Trim the stems to 4 inches and use a fork to lift the clumps gently.
• Dry and cure: Allow the rhizomes to sit in a dry spot for a few days to toughen the skin.
• Pack loosely: Use peat moss or wood shavings in a breathable container.
• Store cool: Find a dark spot between 40°F and 50°F.
• Monitor: Check monthly for rot or extreme dryness.

The secret to successful canna storage is balance. You want to keep the rhizomes dormant and protected from the cold without letting them become bone-dry or soaking wet.

Moving Cannas from Containers

Many gardeners prefer to grow cannas in large pots to decorate patios and decks. If you have your cannas in containers, the storage process is even easier. You have two main options depending on how much space you have.

The first option is to treat them exactly like in-ground cannas. Once the frost hits, cut back the foliage, tip the pot over, and harvest the rhizomes from the soil. This is usually necessary if the plants have become "root-bound" or if the pot is too heavy to move. It also gives you a chance to refresh the soil for next year.

The second option is to store the entire pot. If the container is manageable, simply cut the foliage back and move the whole pot into a cool, dark, frost-free area. Do not water the pot at all during the winter. The dry soil in the pot acts as a natural storage medium. In the spring, you can bring the pot back out, give it a good soak, and wait for the new shoots to appear.

Preparing for Spring Replanting

As winter fades and the days grow longer, you will start to see the first signs of life. In early spring, you can move your storage boxes to a slightly warmer spot to "wake them up." This is the perfect time to finish any dividing you didn't do in the fall.

Wait until the soil temperature in your garden reaches at least 60°F before planting them outside. Cannas love warm soil and will sit dormant and unhappy if they are planted in cold, wet ground too early. In many regions, the right time to plant cannas is around the same time you would plant tomatoes or peppers.

If you have a short growing season, you can give your cannas a head start by planting them in pots indoors about 4 to 6 weeks before the last frost date. Place the pots in a sunny window or under grow lights. By the time the weather is warm enough to move them outside, you will already have several inches of lush green growth, giving you a much earlier display of flowers.

Conclusion

Storing canna bulbs for winter is a simple and rewarding way to preserve the tropical beauty of your garden. By understanding the plant's need for a dormant period and providing a cool, stable environment, you can ensure your cannas return larger and more vigorous each year. At Longfield Gardens, we believe that these small seasonal tasks connect us more deeply to the rhythm of our gardens, making the eventual bloom all the more special.

• Wait for the first frost to signal the start of dormancy.
• Clean and cure the rhizomes to prevent rot during the long winter months.
• Use breathable containers and moisture-regulating materials like peat moss.
• Keep your storage area cool but strictly frost-free.

When the warm spring sun finally returns, you'll be ready to bring those tropical vibes back to your landscape. For more tips on growing beautiful summer-blooming bulbs, explore our other planning guides and variety spotlights. Browse our spring-planted bulbs collection as you plan ahead for next season.

Key Takeaway: Success with cannas is all about timing. Respect the frost in the fall and wait for the warmth in the spring to get the best results from your rhizomes.

FAQ

Can I store canna rhizomes in the refrigerator?

While a refrigerator is cool and dark, it is usually too cold and too dry for canna rhizomes. Most refrigerators are kept around 35°F to 38°F, which can damage the tropical tissues of the bulb. Additionally, the low humidity in a fridge will likely cause the rhizomes to shrivel up completely. A cool basement or insulated garage is a much better choice.

Should I wash the dirt off the rhizomes with a hose?

It is generally better to shake or brush the dirt off rather than using water. Excess moisture is the leading cause of rot during winter storage. If your soil is heavy clay and you absolutely must wash them to see the eyes or remove pests, ensure the rhizomes dry out completely in a well-ventilated area for several days before you pack them into boxes.

What should I do if my stored cannas start sprouting in February?

If your cannas start sprouting early, it usually means your storage area is too warm. Try to move the boxes to a cooler spot to slow them down. If the sprouts are already several inches long, you can either pot them up and grow them indoors near a bright window or simply leave them alone and be very careful not to break the sprouts when you eventually plant them in the garden.

Why did my canna bulbs turn into mush over the winter?

Mushy rhizomes are a sign of rot, which is usually caused by one of two things: either they were stored too wet, or they were exposed to freezing temperatures. To prevent this next year, ensure the rhizomes are well-cured (dried) before packing, use a breathable storage medium like wood shavings, and use a thermometer to make sure your storage area stays above 40°F.

If you need help choosing a storage spot, contact us.