Table of Contents
- Introduction
- Understanding Your USDA Hardiness Zone
- When You Can Leave Cannas in the Ground
- Why Digging Up Cannas is Worth the Effort
- When is the Best Time to Dig?
- How to Dig Up Canna Rhizomes Step-by-Step
- Choosing the Right Storage Medium
- Where to Store Your Cannas
- Winter Maintenance: The "Quick Check"
- Growing Cannas in Containers
- Dividing for More Blooms
- Replanting Your Cannas in Spring
- Simple Troubleshooting for Winter Storage
- The Rewarding Cycle of Canna Gardening
- FAQ
Introduction
There is nothing quite like the tropical drama that canna lilies bring to a summer landscape. Their oversized, banana-like leaves and vibrant, torch-like flowers create a vacation vibe right in your own backyard. Whether you love the fiery reds of 'The President' or the striking striped foliage of 'Phaison,' these plants are remarkably easy to enjoy. At Longfield Gardens, we believe that every gardener can find success with these stunning plants, regardless of where they live, and our canna collection makes it easy to get started.
One of the most common questions we receive is whether these "bulbs"—which are technically underground stems called rhizomes—need to come out of the ground when the weather turns cold. Because cannas are native to tropical and subtropical climates, they thrive in heat but are sensitive to freezing temperatures. Deciding whether to dig them up or leave them in place is the key to ensuring they return with even more vigor next year. If you're still learning how winter temperatures affect plants, the Hardiness Zone Map is a helpful place to start.
This guide will help you determine the best winter plan for your cannas based on your local climate and garden conditions. We will walk you through the simple steps of lifting, storing, and dividing your rhizomes so you can enjoy their bold beauty for many seasons to come. Understanding your garden's needs is the first step toward a successful spring, and the broader Garden Basic Essentials page is full of practical advice for that process.
Understanding Your USDA Hardiness Zone
The answer to whether you need to dig up your canna rhizomes depends almost entirely on your USDA hardiness zone. These zones are a standard way for gardeners to determine which plants are likely to thrive in a specific location based on average annual minimum winter temperatures. Knowing your zone takes the guesswork out of winter garden prep.
Cannas are generally considered hardy in zones 8 through 11. In these warmer regions, the ground rarely freezes deep enough to damage the rhizomes. If you live in these areas, your cannas can stay in the soil year-round. They will go dormant in the winter and sprout fresh new growth once the soil warms up in the spring.
If you live in zones 3 through 6, the winter temperatures are too low for cannas to survive outdoors. In these northern climates, the ground freezes solid, which causes the moisture-rich rhizomes to turn to mush. For gardeners in these zones, digging them up—a process often called "lifting"—is a necessary but simple yearly task. Longfield Gardens also shares its Shipping Information so you can match delivery timing to your planting zone.
Zone 7 is the transition zone. In many cases, cannas can survive a southern New Jersey or Virginia winter if they are planted in a sheltered spot and protected with a thick layer of mulch. However, a particularly harsh winter could still pose a risk. Many gardeners in zone 7 choose to dig up at least a portion of their collection just to be safe.
When You Can Leave Cannas in the Ground
If you are lucky enough to garden in a warm climate, leaving your cannas in the ground is a great way to save time and energy. It also allows the plants to establish large, impressive colonies over several years. However, "leaving them in the ground" does not mean leaving them entirely to their own devices. A little bit of autumn care goes a long way.
Once the first light frost hits and the foliage begins to yellow or turn brown, it is time to tidy up the plants. Use sharp garden shears to cut the stems down to about 3 or 4 inches above the soil line. This keeps the garden looking neat and removes old foliage where pests might try to overwinter.
In zones 7 and 8, adding a "winter blanket" is a smart move. Apply a 4-to-6-inch layer of organic mulch over the planting area. You can use shredded leaves, straw, or wood chips. This layer acts as insulation, keeping the soil temperature more stable and protecting the rhizomes from sudden temperature drops. For more background on canna care, see All About Cannas.
Key Takeaway: If you live in zone 8 or warmer, simply cut back the stems after the first frost and apply a layer of mulch. This protects the roots and keeps your garden tidy until spring.
Why Digging Up Cannas is Worth the Effort
For those in colder climates, digging up cannas might feel like an extra chore, but it actually offers several benefits. Beyond simply keeping the plants alive, lifting the rhizomes gives you a chance to inspect their health and manage their size. Cannas are enthusiastic growers, and their underground rhizomes multiply quickly during a single growing season.
When you dig them up, you will often find that the single rhizome you planted in May has turned into a large clump with several new growing points. This is an easy way to get "free" plants. You can divide these clumps in the fall or spring to expand your garden or share them with friends and neighbors.
Digging also allows you to refresh your garden design. Since cannas are such dominant visual features, you might want to move them to a different spot next year. By lifting them, you have total flexibility on where they will go when the next planting season arrives.
When is the Best 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 freezes hard. The best indicator is the weather itself.
Wait for the first frost of the autumn. You will know it has happened when the lush green leaves of your cannas suddenly turn black or dark brown and go limp. This frost signal tells the plant to stop growing and enter dormancy. It also signals that it is time for you to grab your shovel.
While a light frost kills the leaves, it does not immediately freeze the ground. You usually have a window of a few weeks after the first frost to complete the task. If you live in an area where the ground freezes very early, keep an eye on the long-term forecast and aim to have your cannas safely inside before the daytime temperatures stay below freezing.
How to Dig Up Canna Rhizomes Step-by-Step
Lifting cannas is a straightforward process that requires only a few basic tools: a garden fork or shovel, a pair of pruners, and some storage containers. Following a systematic approach ensures you don't damage the rhizomes during the process.
Step 1: Cut Back the Foliage
Start by cutting the stems down to about 2 to 4 inches above the ground. Removing the heavy stalks makes it much easier to see where you are digging and prevents the long leaves from getting in your way. Do not throw the foliage into your compost pile if you noticed any pest issues during the summer; otherwise, it makes great organic matter.
Step 2: Loosen the Soil
Using a garden fork is often better than a shovel because it is less likely to slice through the rhizomes. Start digging about 6 to 12 inches away from the base of the stems. Cannas spread outward, so the rhizomes may be further from the center than you think. Gently rock the fork back and forth to loosen the soil all the way around the clump.
Step 3: Lift the Clump
Once the soil is loose, slide your tool underneath the clump and pry it upward. Use your hands to help lift the mass of rhizomes out of the hole. Don't worry if the clump is heavy; it is likely full of stored water and nutrients.
Step 4: Remove Excess Soil
Gently shake the clump to remove large chunks of soil. You can use your fingers to brush away more dirt, but avoid being too aggressive. You do not need to wash the rhizomes with water. In fact, keeping them dry is better for the storage process. A little bit of clinging soil is perfectly fine.
Step 3: The Curing Process
This is a step many gardeners skip, but it is vital for preventing rot. Lay the rhizomes out in a dry, frost-free area for a few days. A garage, shed, or covered porch works well. This "curing" period allows the outer skin of the rhizome to toughen up and any remaining soil to dry out completely.
What to do next:
- Cut stems to 4 inches.
- Dig 12 inches away from the base.
- Lift gently with a garden fork.
- Shake off loose soil.
- Let them dry (cure) for 2–3 days in a protected spot.
Choosing the Right Storage Medium
Once your canna rhizomes are cured, they need a cozy place to spend the winter. The goal of storage is to keep them dormant, cool, and just slightly moist so they don't shrivel up completely. However, if they stay too wet, they will rot. Finding the right balance is easy with the right materials.
Common storage mediums include:
- Peat Moss: This is a popular choice because it holds just enough moisture while still allowing for air circulation.
- Vermiculite or Perlite: These lightweight minerals are excellent for keeping rhizomes separated and dry.
- Wood Shavings or Sawdust: Ensure the shavings are from untreated wood. This is an affordable and effective option.
- Newspaper: If you only have a few rhizomes, wrapping them individually in several layers of dry newspaper can work well.
Place a layer of your chosen medium in the bottom of a cardboard box, plastic bin (with holes for ventilation), or a breathable burlap bag. Lay the rhizomes on top so they are not touching each other. Covering them with another layer of the medium helps insulate them and prevents them from drying out too fast.
Where to Store Your Cannas
The location of your winter storage is just as important as the container. You need a spot that is dark, dry, and cool but strictly frost-free. The ideal temperature range is between 40°F and 50°F.
An unheated basement, a crawl space, or a cool closet in an attached garage are usually the best spots. Avoid areas near a furnace or water heater, as the warmth will cause the rhizomes to dry out or try to grow prematurely. Similarly, avoid areas that might drop below freezing, such as an uninsulated shed in a cold climate.
If you choose to use a plastic storage bin, make sure the lid is not airtight. You can drill a few small holes in the sides of the bin to allow gases to escape and fresh air to enter. Without ventilation, moisture can build up inside, leading to mold and rot.
Winter Maintenance: The "Quick Check"
Your work isn't entirely done once the cannas are tucked away. It is a good idea to check on your stored rhizomes once a month during the winter. This simple habit can save your entire collection if an issue arises.
When you check them, look for two things:
- Signs of Rot: If a rhizome feels mushy or has a foul smell, remove it immediately. Rot can spread quickly from one rhizome to the next, so getting rid of the "bad apple" is essential.
- Signs of Shriveling: If the rhizomes look very wrinkled and feel exceptionally light, they are losing too much moisture. Use a spray bottle to lightly mist the storage medium with water. You don't want it wet—just slightly damp to the touch.
Most of the time, you will find that they are sitting perfectly fine, waiting for the return of the sun. This monthly check gives you peace of mind and ensures a high success rate when spring finally arrives.
Growing Cannas in Containers
If you grow your cannas in large pots or planters, the winter routine is even easier. Containers offer a great way to enjoy cannas on patios or in small gardens, and they simplify the "digging" process because you don't actually have to dig. For a compact, container-friendly style, Medium Cannas are a natural fit.
Once the frost hits and you have cut back the foliage, you can simply move the entire container into a frost-free area like a garage or basement. The soil in the pot acts as the storage medium. Do not water the pot during the winter; let the soil dry out completely.
In the spring, about six weeks before the last frost, you can bring the pot back into a warm, sunny spot and begin watering it again to "wake up" the plant. If the canna has outgrown its pot, this is the perfect time to tip it out, divide the rhizomes, and replant them with fresh potting soil.
Dividing for More Blooms
Cannas are generous plants. A single healthy rhizome can easily triple or quadruple in size over a summer. If you don't divide them every few years, the clumps can become so large and crowded that they produce fewer flowers.
The best time to divide is in the spring, just before you replant them. This allows you to see the "eyes" or growth buds more clearly. Each division should have at least one or two of these firm, pointed buds. You can usually pull the rhizomes apart by hand, but if they are very thick, a sharp, clean knife will do the trick.
If you use a knife, let the cut pieces sit in the open air for a day to "callus" or dry over the cut surface before planting. This simple step prevents soil-borne bacteria from entering the fresh cut. Dividing is an easy win for any gardener who wants more color without spending more money.
Replanting Your Cannas in Spring
When the days grow longer and the birds start returning, it is time to think about getting your cannas back into the garden. However, don't rush the process. Because they are tropical, cannas need warm soil to begin growing. For a step-by-step refresh on planting, Grow Canna Flower Bulbs is a useful guide.
Wait until the danger of frost has passed and the soil temperature has reached at least 60°F. A good rule of thumb is to plant your cannas around the same time you would plant tomatoes. If you want a head start, you can plant them in pots indoors about 4 to 6 weeks before the last frost date and then move the established plants outside once the weather is settled.
Choose a spot with full sun—at least 6 to 8 hours of direct light. Cannas are hungry and thirsty plants, so incorporate some compost into the soil and ensure they have access to regular water. Plant the rhizomes about 2 to 3 inches deep and space them 1 to 2 feet apart, depending on the variety's mature size. If you want more detail on spacing, How Far Apart Should Canna Bulbs Be Planted? explains the basics clearly.
Simple Troubleshooting for Winter Storage
Even with the best care, sometimes things don't go exactly as planned. If you encounter an issue, don't be discouraged. Most canna problems have simple solutions.
If your rhizomes didn't survive the winter, it is usually due to one of two things: freezing or rotting. If they were mushy and smelly, they were likely too wet or didn't have enough airflow. If they were dry and brittle, they either didn't have enough insulation or the storage area was too warm.
If your cannas are slow to sprout in the spring, remember that they are heat-lovers. If the spring is particularly cool and rainy, they may stay dormant longer than usual. Patience is key. Once the heat of summer truly arrives, they will quickly make up for lost time with rapid growth and bold blooms.
Key Takeaway: Success with cannas comes down to temperature control. Keep them cool and dry in the winter, and wait for warm soil in the spring.
The Rewarding Cycle of Canna Gardening
There is a deep sense of satisfaction in seeing a plant you cared for all winter emerge from the soil in the spring. Digging up cannas might seem like a lot of steps when written down, but in practice, it only takes an hour or two of work once a year. In exchange, you get years of tropical color and a garden that feels like a private oasis.
By following these simple steps, you can maintain a beautiful collection of cannas indefinitely. Whether you are keeping them in the ground in Georgia or storing them in a basement in Minnesota, these plants are resilient and eager to grow. We love seeing how home gardeners use these versatile plants to transform their spaces.
As you plan your garden for the coming year, remember that gardening is a journey. Each season brings new lessons and new opportunities to see your hard work bloom. We at Longfield Gardens are here to support you with quality plants and the practical advice you need to grow with confidence, and you can always review our Shipping Information as you plan ahead.
- Know your zone to decide whether to dig or mulch.
- Wait for the first frost before lifting rhizomes.
- Cure the rhizomes for a few days to prevent rot.
- Store in a cool, dark, frost-free location in a breathable medium.
- Divide in the spring to multiply your collection.
"The small effort of protecting your cannas during the winter is rewarded tenfold when their lush foliage and brilliant flowers light up the summer garden year after year."
FAQ
Can I leave my cannas in the ground if I live in Zone 6?
In Zone 6, leaving cannas in the ground is very risky. While a particularly mild winter combined with heavy mulching might allow some to survive, the ground usually freezes deep enough to kill the rhizomes. To ensure your plants return, it is best to dig them up and store them indoors.
Do I need to wash the rhizomes before storing them?
It is actually better not to wash them. Excess moisture is the primary cause of rot during winter storage. Simply shake off the loose dirt and let them air dry. A little bit of dry soil left on the rhizomes won't hurt them and may even help protect the skin.
My stored rhizomes have white mold on them. What should I do?
If you see white, fuzzy mold, it usually means there isn't enough air circulation or the storage medium is too damp. Wipe the mold off with a dry cloth and move the rhizomes to a more ventilated container. If the rhizome itself is still firm, it will likely be fine. If it is soft or mushy, discard it.
How do I know if my canna rhizomes are still alive in the spring?
A healthy, living rhizome should feel heavy for its size and firm to the touch, similar to a fresh ginger root or a potato. If you see small, pink or white "eyes" (buds) starting to swell, that is a sure sign the plant is ready to grow. If it is hollow, shriveled, or mushy, it is likely dead.