Introduction
There is nothing quite like the dramatic, tropical flair that cannas bring to a summer garden. With their oversized, banana-like leaves and vibrant blossoms in shades of red, orange, yellow, and pink, they transform any backyard into a lush getaway. At Longfield Gardens, we love how these easy-care plants provide months of color and structure with very little effort during the growing season.
Because cannas are tropical plants, they thrive in the heat of summer but need a little extra care once the weather turns cold. If you live in a region with freezing winters, the key to enjoying these spectacular plants year after year is learning the simple process of lifting and storing them. This practice, often called overwintering, is a rewarding way to build your garden collection without having to start from scratch every spring.
In this guide, we will walk you through everything you need to know about saving your canna rhizomes (the fleshy underground stems often called "bulbs") for the next season. We will cover the best timing for digging, how to clean and prepare them, and the most effective ways to store them until the warmth of spring returns. By following a few straightforward steps, you can ensure your cannas come back bigger and better every year.
Understanding Canna Rhizomes
Before we get into the "how-to" of storage, it helps to understand what we are actually saving. While many gardeners refer to them as bulbs, cannas actually grow from rhizomes. A rhizome is a thick, fleshy underground stem that stores energy and nutrients for the plant.
During the summer, the plant uses this energy to produce those massive leaves and bright flowers. As the season winds down, the plant moves that energy back down into the rhizome to survive the dormant period. When you save your cannas over the winter, you are protecting that stored energy from the killing frost.
The best part about canna rhizomes is that they naturally multiply. If you started the spring with one small rhizome, you will likely find a large, multi-segmented clump by the time autumn arrives. This means that by saving your cannas, you aren't just keeping your current plants—you are actually growing your garden for free.
When to Start the Overwintering Process
Timing is one of the most important factors when it comes to saving canna bulbs over winter. You want to give the plant as much time as possible to store energy, but you must act before the ground itself freezes solid.
In most climates, the signal to start digging is the first "blackening" frost. When a light frost hits, the foliage of the canna will turn brown or black and begin to wilt. This looks a bit sad, but it is actually a helpful sign from nature. It tells the plant that it is time to go dormant.
Wait for this first frost to happen before you dig. This allows the nutrients from the dying leaves to travel down into the rhizome one last time. If you live in an area where frost comes very late or not at all, you can simply wait until the foliage starts to yellow naturally in late autumn.
Key Takeaway: Wait for the first light frost to kill back the foliage before digging. This ensures the rhizome has stored maximum energy for its winter nap.
What to do next:
- Monitor your local weather forecast for the first "killing frost."
- Gather your tools: a garden spade or fork, pruners, and some storage containers.
- Check that your garden labels are still in place so you know which color is which once the leaves are gone.
How to Dig and Lift Canna Rhizomes
Once the foliage has been hit by frost, it is time to get your hands in the dirt. Digging cannas is a simple physical task, but being gentle is the secret to success.
Step 1: Cut Back the Foliage
Before you reach for the shovel, use a pair of sharp garden pruners or loppers to cut the stalks down. You should leave about 2 to 4 inches of the stem attached to the rhizome. This "handle" makes it easier to move the clumps around and helps you remember which side is up when you go to replant them later. Dispose of the blackened leaves in your compost pile or yard waste.
Step 2: Loosen the Soil
Cannas have a surprising way of expanding underground. To avoid slicing through a healthy rhizome, start digging about 6 to 10 inches away from the base of the stems. Use a garden spade or a sturdy garden fork to gently loosen the soil all the way around the clump.
Step 3: Lift the Clump
Once the soil is loose, slide your tool underneath the root mass and pry upward. Most canna clumps will come up easily in one large piece. Don't worry if the clump breaks into smaller sections while you are lifting it; canna rhizomes are quite tough, and these smaller pieces will grow just fine next year.
Cleaning and Curing for Storage
Once the rhizomes are out of the ground, they need a little preparation before they head into storage. This step is often called "curing," and it helps prevent rot and disease while the plants are dormant.
Shaking Off the Soil
Gently shake the clump to remove large chunks of garden soil. You don't need to get them perfectly clean right away. Some gardeners prefer to wash their rhizomes with a garden hose to remove all the dirt, but if you do this, you must be very careful to let them dry completely. Excess moisture is the primary enemy of a dormant rhizome.
The Curing Process
Curing simply means letting the rhizomes air-dry in a protected spot. Find a cool, dry place out of direct sunlight—an unheated garage, a porch, or a shed works perfectly. Lay the rhizomes out in a single layer on top of newspaper or cardboard.
Let them sit for 2 to 7 days. During this time, the outer "skin" of the rhizome will toughen up slightly, and any remaining soil will dry out and fall off. This toughening process creates a natural barrier against rot.
Inspecting Your Harvest
Before you pack them away for the winter, take a moment to look over each piece. A healthy canna rhizome should feel firm, like a fresh ginger root or a potato. If you find any sections that feel soft, mushy, or show signs of heavy insect damage, trim those parts away or discard the piece entirely. Starting with healthy material is the best way to ensure success in the spring. For more help, see this canna rhizome identification guide.
Choosing the Best Storage Method
There are several ways to store canna rhizomes, and the best one for you usually depends on the space you have available and the humidity of your home. The goal is to keep them cool (between 40°F and 50°F) and dark, with just enough moisture to keep them from shriveling, but not so much that they grow mold. This canna storage guide offers additional guidance on maintaining the right conditions.
The Bin and Bedding Method
This is the most common and reliable method. Find a sturdy cardboard box, a plastic bin with air holes, or even a paper grocery bag.
- Place a layer of "bedding material" at the bottom. We recommend using slightly damp peat moss, vermiculite, or sawdust.
- Lay your rhizomes on top, making sure they aren't touching each other.
- Cover them with another layer of bedding.
- Repeat until the container is full, ending with a layer of bedding on top.
The Newspaper Wrap
If you only have a few cannas, you can wrap each rhizome individually in several layers of dry newspaper. Place the wrapped bundles into a crate or box. The newspaper acts as insulation and helps regulate moisture levels.
The Plastic Bag Trick
Some gardeners use plastic grocery bags or trash bags, but this requires caution. If you use plastic, you must poke several large holes in the sides of the bag to allow for air circulation. Without airflow, the moisture trapped inside will almost certainly cause the rhizomes to rot.
Key Takeaway: The "Golden Rule" of storage is cool, dark, and slightly damp. If the storage area is too warm, the plants may try to grow; if it's too cold, they will freeze and die.
What to do next:
- Label your storage containers with the variety name and the date.
- Find a spot in your basement, crawl space, or an attached garage that stays cool but never drops below freezing.
- Set a reminder on your calendar to check the rhizomes once a month throughout the winter.
Overwintering Cannas in Containers
If you grow your cannas in large pots or patio containers, you have a shortcut available. You don't necessarily have to dig the rhizomes out of the soil.
When the first frost hits, cut the foliage back to about 2 inches. Then, simply move the entire pot into a frost-free area like a basement or a cool closet. The soil in the pot will act as a natural insulator for the rhizomes. For detailed container guidance, read how to plant canna lily bulbs in pots.
Stop watering the container entirely once you move it indoors. The soil should stay dry through the winter to keep the plant in its dormant state. In the spring, you can move the pot back outside, start watering again, and watch the new shoots emerge. This is a great option for busy gardeners or those with limited storage space.
Winter Maintenance and Troubleshooting
Saving canna bulbs over winter is not a "set it and forget it" task. To ensure the highest survival rate, you should check on your stored rhizomes about once a month.
Monitoring Moisture
During your monthly check, feel a few of the rhizomes.
- If they feel shriveled or brittle: The storage environment is too dry. Lightly mist the bedding material with a spray bottle. You want it to be barely damp, not wet.
- If you see fuzzy mold or mushy spots: The environment is too wet or there isn't enough airflow. Remove any rotting pieces immediately so the problem doesn't spread. If the bedding material feels soggy, replace it with fresh, dry material.
Managing Pests
Sometimes, small critters like mice or certain insects might find your stored rhizomes to be a tasty winter snack. If you notice signs of chewing, consider moving your storage bins to a more secure location or using plastic bins with lids (as long as you provide plenty of ventilation holes).
Preparing for Spring Planting
As the days get longer and the ground begins to thaw, your cannas will naturally start to "wake up." You might even see small white or pink buds, called "eyes," starting to sprout while the rhizomes are still in their winter boxes.
Dividing Your Clumps
Early spring is the perfect time to divide your canna rhizomes. If you have a large clump, you can use a clean, sharp knife to cut it into smaller sections. Each section should have at least one or two healthy-looking "eyes." Let the cut ends dry and callus over for a day before planting. This is how you turn three or four canna plants into a whole hedge of tropical color!
Waking Them Up Early
If you want to get a head start on the season, you can "pre-start" your cannas indoors about 4 to 6 weeks before the last expected frost. Plant the rhizomes in pots with potting soil and place them in a warm, sunny window. By the time the weather is warm enough to move them outside, you will already have several inches of lush green growth.
Moving Outdoors
Wait until the soil has warmed up and all danger of frost has passed before planting your cannas in the garden. They are true sun-lovers and will perform best when planted in a spot that receives at least 6 to 8 hours of direct sunlight.
Hardiness Zones and Winter Survival
Whether or not you need to dig your cannas depends entirely on where you live. The USDA Hardiness Zone guide is a helpful tool for determining your local winter conditions.
- Zones 8 to 11: In these warmer climates, cannas can usually stay in the ground year-round. After the first frost, simply cut the foliage back and apply a thick layer of mulch (about 4 to 6 inches) to protect the rhizomes from occasional cold snaps.
- Zone 7: This is a "buffer" zone. In mild winters, cannas may survive in the ground with heavy mulching, especially if they are planted near a south-facing wall. However, to be safe, many gardeners in Zone 7 choose to lift and store their favorite varieties.
- Zones 3 to 6: In these regions, the ground freezes deep enough to kill canna rhizomes. Digging and storing them indoors is a requirement for survival.
At Longfield Gardens, we want you to feel confident in your garden. No matter your zone, the process of saving cannas is a simple way to ensure your garden remains vibrant and full of life year after year.
Conclusion
Saving canna bulbs over winter is a simple, satisfying way to extend the life of your tropical garden. By waiting for the first frost, carefully lifting the rhizomes, and providing a cool, dry place for them to rest, you are setting the stage for a spectacular display next summer. This cycle of growth, dormancy, and reawakening is one of the most rewarding parts of gardening. It allows you to connect with the seasons and watch your garden grow in size and beauty without a significant investment of time or money.
- Wait for the first frost to signal dormancy before you dig.
- Cure rhizomes for a few days to toughen the skin and prevent rot.
- Store in a cool, dark, frost-free location using peat moss or newspaper.
- Check monthly to ensure moisture levels are just right.
"The beauty of cannas is that they give so much for so little. A few minutes of work in the fall ensures a lifetime of tropical color in your backyard."
We are here to help you every step of the way, from choosing the right varieties to providing the tips you need for year-round success. When you are ready to expand your collection or try a new color, we invite you to explore the Tall Cannas collection available at Longfield Gardens. Happy gardening, and enjoy the peace of mind that comes with knowing your beautiful cannas are safe and sound for the winter.
FAQ
Can I store canna rhizomes in my garage?
You can store them in a garage as long as the temperature stays above freezing. If your garage is uninsulated and temperatures drop below 32°F, the rhizomes will freeze and turn to mush. An attached garage or a basement is usually a safer bet for consistent temperatures.
Do I have to wash the dirt off before storing?
It isn't strictly necessary to wash them, and sometimes it's better not to. Shaking off the loose soil is usually enough. If you do wash them, you must ensure they are 100% dry before packing them away, as any trapped water can lead to rot and fungal issues during the winter.
What if my canna rhizomes look shriveled in February?
If the rhizomes look very wrinkled or feel light and brittle, they are losing too much moisture. Give them a light misting with water and consider adding more bedding material, like damp peat moss, to their container. They should plump back up slightly and stay healthy until planting time.
When is the best time to divide my cannas?
While you can divide them in the fall, most gardeners find it easier to do in the spring. In the spring, the "eyes" (growth points) are more visible, making it easier to see exactly where to cut. This ensures that every piece you plant has the potential to grow into a healthy new stalk.
