Do I Need to Dig Up Canna Bulbs?

Table of Contents

1. Introduction
2. Understanding Your USDA Hardiness Zone
3. When Is the Right Time to Dig?
4. Preparing the Plants for Lifting
5. The Best Way to Dig Up Canna Rhizomes
6. Cleaning and Inspecting Your Rhizomes
7. The Importance of Curing
8. Choosing the Right Storage Medium
9. Packing Your Cannas for the Winter
10. Finding the Perfect Storage Spot
11. Mid-Winter Check-Ups
12. Dividing Canna Rhizomes
13. Transitioning from Pots to Storage
14. Looking Forward to Spring
15. Overwintering Cannas in the Ground
16. Common Myths About Canna Storage
17. Practical Steps for Success
18. Conclusion
19. FAQ

Introduction

Canna lilies are the ultimate showstoppers of the summer garden. Their oversized, banana-like leaves and brilliant, tropical blooms bring an undeniable energy to borders and patio containers. If you have spent the summer enjoying these architectural wonders, you might be wondering how to ensure they return even bigger and better next year. At Longfield Gardens, we want to make sure your gardening experience is as rewarding as possible, which means helping you navigate the change of seasons with confidence.

The answer to whether you need to dig up your canna bulbs—which are technically called rhizomes—depends almost entirely on where you live. While these plants are rugged and fast-growing, they have a "tender" nature, meaning they cannot survive a deep freeze. For many gardeners in the United States, a little bit of autumn effort is the key to preserving these beautiful plants for many seasons to come. For shipping details by zone, see our Shipping Information.

This guide will help you determine if your local climate requires lifting your cannas and provide a simple, step-by-step process for storing them safely through the winter. Whether you are a beginner or an experienced gardener, you will find that overwintering cannas is a straightforward and satisfying task. Our goal is to help you protect your garden investment so you can enjoy another year of spectacular tropical color. For a broader overview, see our All About Cannas.

Understanding Your USDA Hardiness Zone

The most important factor in deciding whether to dig up your cannas is your USDA hardiness zone. These zones are based on the average minimum winter temperature in your area. Because cannas are tropical and subtropical plants, they have specific temperature limits for survival.

In zones 8 through 11, canna rhizomes can usually stay in the ground all year. In these warmer climates, the soil rarely freezes deep enough to damage the rhizomes. Gardeners in these areas can simply cut the foliage back and perhaps add a layer of mulch for extra protection.

If you live in zones 3 through 6, you will definitely need to dig up your cannas. In these regions, the ground freezes solid, which would turn the moisture-rich rhizomes into mush. By lifting them and storing them indoors, you are essentially giving them a cozy place to nap until the warmth of spring returns.

Zone 7 is the "bridge" zone. In a mild winter, cannas may survive in the ground with a thick 6-inch layer of mulch, such as straw or shredded leaves. However, if a particularly cold winter arrives, those rhizomes might not make it. Many gardeners in zone 7 choose to dig them up just to be safe, especially if they have a favorite variety they don't want to lose. If you want a bigger statement next season, browse our Tall Cannas collection.

When Is the Right Time to Dig?

Timing is everything when it comes to lifting cannas. You want to give the plants as much time as possible to store energy in their rhizomes, but you must get them out of the ground before the soil itself freezes.

The best indicator is the first "blackening" frost. When a light frost hits, the lush green or bronze foliage of your cannas will turn brown or black and wilt. This is the plant's natural signal that it is time to go dormant. Do not worry if the leaves look a bit messy after a frost; the rhizome underground is still perfectly safe.

We recommend waiting for this first frost because it tells the plant to stop growing and start resting. If you dig them up too early while the leaves are still vibrant and green, the rhizome may not have stored enough carbohydrates to last through the long winter. Once that frost hits, you usually have a window of a week or two to get them out of the ground before a harder, deeper freeze arrives.

Key Takeaway: Wait for the first light frost to blacken the leaves before you start digging. This ensures the plant has stored maximum energy for its winter dormancy.

Preparing the Plants for Lifting

Before you grab your shovel, you need to prepare the top of the plant. Start by cutting the stems back. Use a clean pair of garden shears or a sharp knife to cut the stalks down to about 2 to 4 inches above the soil line.

Removing the bulk of the foliage makes the digging process much easier. It also allows you to see exactly where the base of the plant is so you don't accidentally slice through the rhizomes. These stalks will serve as a "handle" of sorts while you are lifting the clumps, although you should always support the weight of the clump from underneath.

Once the stalks are trimmed, clear away any mulch or garden debris from around the base. This gives you a clear view of the soil and helps you spot any offsets or smaller rhizomes that might have spread out during the summer.

The Best Way to Dig Up Canna Rhizomes

To lift cannas successfully, the goal is to keep the rhizome clumps as intact as possible. Canna rhizomes can grow quite large over a single summer, often forming dense, heavy mats.

1. Start wide: Position your garden fork or spade about 12 inches away from the main stem. Digging too close is the most common way rhizomes get nicked or cut.
2. Loosen the soil: Circle the plant, pushing your tool deep into the ground and gently prying upward. This loosens the soil and severs the smaller feeder roots without damaging the main storage organ.
3. Lift from below: Once the soil is loose all the way around, slide your fork underneath the center of the clump and lift. If the clump is very large, you may need to lift it in sections, but try to keep the main pieces whole for now.
4. Shake off the excess: Gently shake the clump to remove large chunks of soil. You don't need to get them perfectly clean yet, but removing the heavy garden soil makes them easier to carry and process.

At our trial garden, we find that a garden fork is often better than a shovel for this task. The tines of a fork can move through the soil and around the rhizomes more easily than a solid blade, reducing the risk of accidental damage.

Cleaning and Inspecting Your Rhizomes

Once the cannas are out of the ground, move them to a workspace like a driveway, a lawn, or a potting bench. You can use a garden hose with a gentle spray to wash away the remaining soil. While some gardeners prefer to leave a little soil on, washing them makes it much easier to inspect for any signs of trouble.

As you clean them, look for any soft spots, signs of rot, or damage from insects. Healthy canna rhizomes should feel firm, similar to a fresh potato. If you find a small area of rot, you can usually trim it away with a clean knife. If a rhizome is completely soft or smells unpleasant, it is best to discard it to prevent any issues from spreading to the healthy ones.

This is also a great time to remove any remaining dead roots or small, dangling bits that don't look substantial. You want your stored rhizomes to be as clean and healthy as possible before they go into storage.

The Importance of Curing

Curing is a step that many beginner gardeners skip, but it is vital for long-term storage success. Curing is simply the process of letting the rhizomes air-dry for a few days before you pack them away.

When you first dig up cannas, the outer skin of the rhizome is often thin and easily damaged. Drying them in a protected area—like a garage, a shed, or a covered porch—allows that skin to toughen up. This "curing" process creates a protective barrier that helps prevent the rhizome from drying out too much or rotting during the winter.

Place your cleaned rhizomes in a single layer on a piece of cardboard or a newspaper. Keep them out of direct sunlight and away from freezing temperatures. A few days is usually enough. You will notice the surface feels dry and slightly corky to the touch. Once they reach this stage, they are ready for their winter home.

Choosing the Right Storage Medium

The secret to successful overwintering is finding the perfect balance of moisture. If the storage environment is too wet, the rhizomes will rot. If it is too dry, they will shrivel up and lose their vitality. Using a storage medium helps regulate this.

There are several excellent options for packing your cannas:

• Peat moss: This is a classic choice because it holds a tiny bit of moisture but stays airy.
• Vermiculite or Perlite: These are lightweight and excellent at preventing rot.
• Wood shavings: Often sold as pet bedding, these provide good airflow and cushioning.
• Dry sand: A traditional method that works well in very cool basements.

We recommend using slightly dampened peat moss or wood shavings. The goal is "barely moist"—if you squeeze a handful, it should not drip water, but it should feel cool and not dusty. This provides just enough humidity to keep the rhizome alive without encouraging mold.

Packing Your Cannas for the Winter

Once you have your medium ready, find a breathable container. Cardboard boxes, paper bags, or plastic bins with holes drilled in the sides all work well. Avoid airtight plastic containers, as these trap moisture and almost always lead to rot.

1. Layer the bottom: Place a 2-inch layer of your chosen medium in the bottom of the container.
2. Arrange the rhizomes: Place the rhizomes in the box so they are not touching each other. This ensures that if one rhizome happens to develop a soft spot, it won't immediately spoil its neighbors.
3. Cover and repeat: Add more medium until the rhizomes are completely covered. If you have a deep box, you can add another layer of rhizomes and cover them again.
4. Label everything: It is very easy to forget which variety is which by the time April rolls around. Use a permanent marker to write the variety name and color on the outside of the box or on a tag tucked inside.

What to do next:

• Check your storage area temperature (40-50°F is ideal).
• Gather your boxes and peat moss before the first frost hits.
• Clear a space in your garage or basement for the curing process.

Finding the Perfect Storage Spot

Where you keep your boxes is just as important as how you pack them. Canna rhizomes need a "Goldilocks" temperature—not too hot and not too cold.

The ideal temperature range is between 40°F and 50°F. This is cool enough to keep the plants in a deep sleep, but warm enough that they never risk freezing. A cool basement, a crawl space, or an insulated garage that stays above freezing are usually the best spots.

Avoid areas near furnaces or water heaters, as these spots are often too warm and dry, which can cause the rhizomes to wake up too early or shrivel. Likewise, don't leave them in an unheated shed where the temperature will drop below freezing, as this will kill the rhizomes even if they are packed in boxes.

Mid-Winter Check-Ups

Gardening is a year-round activity, even when the plants are dormant. We recommend checking on your stored cannas about once a month during the winter. This only takes a few minutes but can save your entire collection.

Open the boxes and feel a few of the rhizomes. If they feel firm and look the same as when you packed them, everything is going well.

If you notice any rhizomes starting to look shriveled or wrinkled like a raisin, the environment is too dry. You can lightly mist the storage medium with a spray bottle filled with water. Be careful not to overdo it; you just want to add a tiny bit of humidity back into the air.

If you find a rhizome that has turned soft or shows fuzzy mold, remove it immediately. Check the surrounding rhizomes to make sure they are still dry and firm. This simple monthly check-up ensures that small issues don't turn into big ones.

Dividing Canna Rhizomes

One of the most exciting things about digging up cannas is seeing how much they have grown. A single rhizome planted in the spring can easily turn into a large clump with five or ten new growing points by autumn. This means you can have many more plants next year for free!

You can divide your cannas either in the fall before you store them or in the spring before you replant. Many gardeners prefer the spring because the "eyes" (the small bumps where new growth will emerge) are more visible.

To divide, simply pull the clump apart or use a clean knife to cut the rhizome into smaller sections. Each piece should have at least one or two healthy "eyes." Each of these sections will grow into a full-sized, blooming plant during the next growing season. Dividing your cannas every year or two also keeps the plants vigorous and prevents the clumps from becoming too crowded.

Transitioning from Pots to Storage

If you grow your cannas in containers, the process is even simpler. For more compact options, browse our Short Cannas collection. When the frost hits and the foliage dies back, you have two choices. You can either dig the rhizomes out of the pot and store them in boxes as described above, or you can store the entire pot.

If you have space in a cool, frost-free basement or garage, you can simply cut the foliage back and move the entire container indoors. Stop watering completely. The soil in the pot acts as the storage medium. In the spring, you can pull the rhizomes out, refresh the soil, and start them growing again. This is a great time-saver for those with limited space for boxes and peat moss.

Looking Forward to Spring

As the days grow longer and the soil begins to warm, your stored cannas will naturally start to "wake up." You might even see small white or pink sprouts beginning to emerge from the rhizomes in their storage boxes. This is an exciting sign that a new season is just around the corner!

At Longfield Gardens, we recommend waiting until the danger of frost has passed and the soil temperature reaches at least 60°F before planting your cannas back into the garden. If you want step-by-step planting details for spring, see our How to Plant Canna Bulbs for a Stunning Tropical Garden. Because they are heat-lovers, they won't do much in cold, wet spring soil. If you want a head start, you can pot them up indoors about four to six weeks before your last frost date. This gives them a "running start" so they are already several inches tall by the time they move outside.

"The effort you put into protecting your cannas during the winter pays off tenfold when those first tropical leaves unfurl in the summer sun."

Overwintering Cannas in the Ground

For those lucky enough to live in zones 8 through 11, the "digging" part of the season is optional. However, "overwintering" still requires a little bit of care to ensure the plants return beautifully.

Once the foliage begins to yellow or is hit by a light frost, cut the stalks down to about 3 or 4 inches. In these warmer zones, you don't necessarily have to wait for a frost if you want to tidy up the garden earlier.

Even in warm climates, a sudden cold snap can happen. Applying a 3-inch layer of organic mulch over the top of the cut-back plants is a smart insurance policy. This mulch helps keep the soil temperature consistent and protects the shallowest parts of the rhizome from frost nipping. In the spring, simply pull the mulch back to allow the sun to warm the soil and trigger new growth.

Common Myths About Canna Storage

There is a lot of advice floating around the internet about cannas, and some of it can be a bit confusing. Let's clear up a few common misconceptions:

Myth 1: You must wash them with bleach. Some people suggest a bleach dip to prevent rot. While cleanliness is good, this is usually unnecessary and can actually damage the delicate eyes of the rhizome. Fresh air, proper curing, and the right storage medium are much more effective.

Myth 2: They will "freeze out" the soil pests. While cold temperatures can reduce some pest populations, many garden insects are just as good at overwintering as your plants are. The best way to manage pests is through healthy soil and proper site selection in the spring.

Myth 3: You can't store them if they were "damaged" during digging. If you accidentally nick a rhizome with your shovel, don't throw it away! Simply let the cut end dry and "callus" over during the curing process. As long as the rest of the rhizome is firm and has an eye, it will likely grow just fine.

Practical Steps for Success

To make your winter storage as easy as possible, keep these simple rules in mind:

• Keep it simple: You don't need fancy equipment. Cardboard boxes and newspaper work perfectly.
• Air is your friend: Never use airtight plastic. Your rhizomes are living things and need to breathe.
• Cool, not cold: Aim for that 40-50°F range. If you are comfortable in a light sweater, it's likely a good temperature for your cannas.
• Label clearly: You will thank yourself in May when you know exactly where to plant your City of Portland versus your "Red King Humbert."

By following these steps, you take the guesswork out of canna care. It turns a potential "chore" into a simple seasonal rhythm that protects your favorite plants.

Conclusion

Digging up canna bulbs—or rhizomes—is a simple, rewarding part of the gardening cycle for anyone living in a climate with freezing winters. By understanding your zone and following the natural cues of the first frost, you can easily preserve these tropical treasures. If you want a balanced, mid-height look next year, browse our Medium Cannas collection.

We are here to help you grow a more beautiful home landscape, and 100% Quality Guarantee means your planting season starts with confidence. With a little bit of preparation and the right storage conditions, your cannas will be ready to burst back into life as soon as the summer heat returns.

• Wait for the first frost to signal dormancy before digging.
• Cure the rhizomes for a few days to toughen the skin.
• Store in a breathable container with a slightly damp medium like peat moss.
• Maintain a cool, frost-free storage temperature between 40°F and 50°F.

The secret to a lush, tropical garden year after year is simply working with the seasons. Protecting your cannas over the winter is a small task that yields huge, colorful rewards.

Ready to add more color to your landscape? You can explore our canna collection to find the perfect companions for your cannas.

FAQ

What happens if I don't dig up my canna bulbs in a cold climate?

If you live in a region where the ground freezes (Zone 6 and colder) and you leave your cannas in the ground, the rhizomes will freeze and die. Since they are composed mostly of water, the freezing temperatures turn the plant tissue into mush, meaning they will not grow back in the spring.

Can I store canna rhizomes in the garage?

You can store them in the garage as long as the temperature stays above freezing (32°F) all winter. An insulated garage is often perfect, but in very cold climates, an unheated garage might get too cold, which would kill the rhizomes.

Do I need to water my canna bulbs while they are in storage?

Generally, no, you do not want to water them. However, if you check them mid-winter and the rhizomes look very shriveled or the peat moss is bone-dry, you can lightly mist the medium with a spray bottle to add a tiny bit of humidity.

How do I know if my stored canna rhizome is dead?

A dead or dying rhizome will feel soft, mushy, or hollow when squeezed. Healthy rhizomes should feel firm and heavy for their size. If you see fuzzy mold or smell a foul odor, that is also a sign that the rhizome has rotted and should be discarded.