Table of Contents
- Introduction
- Understanding Canna Lily Hardiness
- Timing Your Harvest
- Preparing the Tools for the Job
- Step-by-Step Lifting Process
- Curing: The Secret to Long-Term Storage
- Choosing the Right Storage Medium
- Identifying and Labeling
- The Ideal Storage Environment
- Maintaining Your Bulbs Through Winter
- Storing Canna Lilies in Pots
- Dividing Cannas During the Winter Process
- Transitioning to Spring
- Common Myths About Wintering Cannas
- Planning Your Garden Display
- Summary of the Wintering Process
- Conclusion
- FAQ
Introduction
Canna lilies are the undisputed stars of the summer garden. With their towering heights, tropical foliage, and vibrant blooms, they bring an exotic energy to any landscape. At Longfield Gardens, we know how much joy these plants provide from midsummer through the first chill of autumn. While these tropical beauties thrive in the heat, they need a little extra care to survive the winter in most regions.
Learning the simple steps for wintering canna lily bulbs—which are technically rhizomes—allows you to enjoy your favorite varieties year after year. This process is rewarding and budget-friendly, as your plants will often grow larger and produce more blooms each season. This guide is for any gardener who wants to keep their cannas safe, healthy, and ready for a spectacular comeback. By following a few basic storage rules, you can ensure your cannas remain a highlight of your garden for years to come.
Understanding Canna Lily Hardiness
Canna lilies are native to tropical and subtropical climates. In these warm environments, they grow as perennials, staying in the ground all year. However, most American gardens fall into regions where the ground freezes during the winter. Because canna rhizomes are full of moisture, they cannot survive a hard freeze.
In USDA hardiness zones 8 through 11, canna lilies can usually stay in the ground year-round. Gardeners in these areas might simply apply a thick layer of mulch to provide a little extra protection. For those of us in zones 7 and colder, lifting and storing the rhizomes is a necessary part of the gardening calendar.
Determining your hardiness zone is the first step in planning your winter care. If you are unsure of your zone, you can find it on our hardiness zone map or through local agricultural extension services. Knowing your zone helps you decide if you need to lift your bulbs or if a simple layer of straw will suffice. Even in borderline zones, many gardeners choose to lift their favorite varieties just to be safe.
Timing Your Harvest
The most important rule for wintering canna lily bulbs is to let nature tell you when it is time. You should wait for the first "killing frost" to hit your garden. This is a frost that is cold enough to turn the lush green leaves of your cannas brown or black.
While it might be tempting to tidy up the garden during a warm spell in early autumn, waiting for this frost is beneficial for the plant. As the temperatures drop, the canna lily begins to move its energy from the leaves and stems down into the rhizome. This stored energy is what powers the plant’s growth the following spring.
Once the foliage has withered from the cold, you have a window of about a week or two to get the rhizomes out of the ground. You want to act before the ground itself freezes solid. A frozen rhizome will turn to mush and will not survive the winter. Keeping an eye on the local weather forecast during October and November will help you pick the perfect weekend for this garden task.
Preparing the Tools for the Job
Gathering your supplies before you head into the garden makes the process much smoother. You do not need expensive equipment to successfully winter your canna lilies. A few basic garden tools will do the trick.
- Garden Fork: A sturdy garden fork is often better than a shovel. It allows you to lift the soil and the rhizomes without slicing through the roots.
- Pruning Shears or a Garden Knife: You will need these to cut back the heavy stalks.
- Garden Hose (Optional): This can be used for a light rinse, though many gardeners prefer to brush off dry soil.
- Labels and a Permanent Marker: This is a vital step often forgotten. Once the rhizomes are out of the dirt, they all look very similar.
- Storage Containers: Cardboard boxes, plastic bins with ventilation, or even paper bags work well.
- Packing Material: Peat moss, vermiculite, perlite, or wood shavings help regulate moisture during storage.
Key Takeaway: Successful wintering starts with patience. Wait for the first frost to blacken the leaves, which signals the plant to store energy for next year.
Step-by-Step Lifting Process
Lifting canna lilies is a straightforward process, but it requires a gentle touch. Canna rhizomes grow horizontally and can spread quite far from the original planting point. Follow these steps to get them out of the ground safely.
Cutting Back the Stalks
Start by cutting the stems back to about 2 to 4 inches above the soil line. Removing the bulky foliage first makes it much easier to see where the base of the plant is. Use sharp shears to ensure a clean cut, which helps prevent disease. You can compost the healthy green foliage, but if the leaves show signs of pests or disease, it is best to discard them.
Digging and Lifting
Move about 6 to 10 inches away from the base of the stems. This distance helps you avoid hitting the rhizomes with your fork. Insert the garden fork deep into the soil and gently pry upward. Work your way around the entire clump, loosening the soil as you go.
Once the soil is loose, you can lift the entire clump out of the ground. Canna rhizomes often grow in large, heavy masses. If the clump is too heavy to lift all at once, you can use your fork to gently break it into smaller, more manageable sections.
Cleaning the Rhizomes
Shake the clump gently to remove large chunks of soil. You can use your hands to brush away the remaining dirt. While some gardeners use a hose to wash the rhizomes, we generally recommend keeping them as dry as possible. Excess water at this stage can lead to rot during storage. If the soil is very wet and muddy, let the rhizomes sit in a garage or shed for a few hours to dry before you try to remove the rest of the dirt.
Curing: The Secret to Long-Term Storage
Curing is the process of allowing the outer skin of the rhizome to dry and toughen up. This is a critical step that many beginners skip. A well-cured rhizome is much more resistant to mold and rot over the winter months.
After you have cleaned the rhizomes, find a cool, dry place out of direct sunlight. A garage, a shed, or a covered porch works perfectly. Spread the cannas out in a single layer. Do not stack them, as air needs to circulate around each piece.
Let the rhizomes sit for two to three days. During this time, any small nicks or cuts from the digging process will "callus" over. The remaining soil will become dry and brittle, making it easy to flick away with your thumb. Once the surface feels dry and the skin looks a bit more rugged, they are ready for their winter home.
Choosing the Right Storage Medium
The goal of winter storage is to keep the rhizomes dormant. You want to prevent them from drying out completely (shriveling) and protect them from too much moisture (rotting). Choosing the right packing material helps maintain this delicate balance.
Peat Moss or Coco Coir
Peat moss is a favorite among gardeners because it is excellent at regulating moisture. It is naturally slightly acidic, which can help discourage fungal growth. If you use peat moss, it should be barely damp—just enough that it doesn't feel like dust, but not wet enough to squeeze out any water.
Wood Shavings or Sawdust
Pine or cedar shavings, often sold as pet bedding, are another great option. They are very breathable and provide good insulation against temperature fluctuations. Shavings are also easy to clean off the rhizomes when spring arrives.
Paper Bags or Cardboard Boxes
For gardeners in climates that aren't excessively dry, simply wrapping the rhizomes in several layers of newspaper and placing them in a cardboard box can work well. The paper absorbs excess moisture while still allowing the plant to breathe.
Vermiculite or Perlite
These lightweight mineral products are excellent for storage because they are sterile. They do not hold onto much water, which makes them a safe choice if you are worried about rot.
Key Takeaway: The "Goldilocks" rule applies to moisture: the storage medium should be neither bone-dry nor soaking wet. A light misting of the medium is usually all you need.
Identifying and Labeling
One of the most common mistakes gardeners make is forgetting to label their rhizomes. When you are standing in your garden in May, it is impossible to tell the difference between a 'Red King Humbert' and a City of Portland just by looking at the brown roots.
We recommend labeling each variety as you pack them away. You can write the name directly on the dried rhizome with a soft permanent marker. Alternatively, you can place the rhizomes in a paper bag with the name written on the outside, or use plastic plant tags tied to the stems with garden twine. If you have different heights or leaf colors (like bronze vs. green), make a note of those details on the label too.
The Ideal Storage Environment
Location is everything when it comes to wintering canna lily bulbs. You need a spot that stays consistently cool but never reaches the freezing point.
The ideal temperature range is between 40°F and 50°F. If the area is too warm, like a heated basement, the cannas may try to start growing too early or they might shrivel up. If the area is too cold, the cells in the rhizome will rupture, and the plant will die.
Possible Storage Locations:
- Unheated Basement: Often the best choice, as it stays cool and dark.
- Crawlspace: Usually maintains a very stable temperature.
- Insulated Garage: Be careful here; a garage can get too cold during a polar vortex. Keep the boxes off the concrete floor by placing them on a shelf or a wooden pallet.
- Root Cellar: These are designed for this exact purpose and provide excellent conditions.
Check the temperature of your chosen spot with a simple thermometer before committing your plants to it for the season. Avoid areas near furnaces, water heaters, or drafty windows.
Maintaining Your Bulbs Through Winter
Your job isn't quite finished once the boxes are tucked away. Canna lilies benefit from a quick "wellness check" once a month during the winter. This allows you to catch any potential issues before they ruin the entire batch.
Open your containers and look for two things: rot and shriveling.
Dealing with Rot
If you see a rhizome that looks soft, mushy, or has a foul smell, remove it immediately. Rot can spread quickly through a box of bulbs. If only a small portion of a large rhizome is soft, you can sometimes cut the bad part away and let the healthy part dry before putting it back. However, if in doubt, it is better to discard the one bad bulb to save the rest.
Dealing with Shriveling
If the rhizomes look very wrinkled and feel light or hollow, they are losing too much moisture. To fix this, use a spray bottle to lightly mist the storage medium (the peat moss or shavings). You don't want to soak the bulbs; you just want to increase the humidity in the container.
What to Do Next: Winter Care
- Check your stored cannas once every 4 to 6 weeks.
- Remove any rhizomes that feel soft or mushy.
- Lightly mist the packing material if it feels bone-dry.
- Ensure the storage area remains between 40°F and 50°F.
Storing Canna Lilies in Pots
Many gardeners enjoy growing Medium Cannas in large decorative containers. If you have pot-grown cannas, you have a slightly easier path for the winter. You don't necessarily have to dig them up.
Once the frost has hit the foliage, cut the stalks back just as you would for garden-grown plants. Move the entire pot into a cool, frost-free area like a garage or basement. Stop watering the pot entirely. The soil will dry out, and the plant will go into a natural state of dormancy.
In the spring, you can simply bring the pot back outside, refresh the top few inches of soil with new compost, and start watering again. However, keep in mind that cannas grow very quickly. After a year or two in the same pot, the rhizomes will likely become "root-bound." Every couple of years, it is a good idea to tip the pot over, divide the rhizomes, and replant them with fresh potting mix.
Dividing Cannas During the Winter Process
The winter lifting process is the perfect time to multiply your garden. Canna rhizomes are vigorous growers. A single rhizome planted in May can turn into a large clump by October.
You can divide the rhizomes either in the fall before you store them or in the spring before you plant them. Most experts at Longfield Gardens suggest waiting until spring to do the final division. This is because the rhizomes are easier to handle when they are slightly more hydrated, and you can clearly see where the new "eyes" (growing points) are located.
When you do divide them, use a clean, sharp knife. Each piece should have at least one or two "eyes." These look like small, pointed bumps on the surface of the rhizome. Let any fresh cuts dry for a day before planting to prevent soil-borne diseases from entering the plant.
Transitioning to Spring
As the days get longer and the threat of frost passes, it is time to wake up your cannas. This is often the most exciting part of the process for any gardener.
In most areas, you can start your canna lilies indoors about 4 to 6 weeks before the last expected frost date. This gives you a "head start" on the season, leading to earlier blooms. Simply place the rhizomes in pots with some potting soil, keep them in a warm, sunny spot, and water them lightly.
If you prefer to plant directly into the garden, wait until the soil is warm. A soil temperature of at least 60°F is ideal. Planting into cold, wet spring soil can cause the rhizomes to rot before they have a chance to grow. Canna lilies love heat, so they won't mind waiting until the weather is consistently mild.
Common Myths About Wintering Cannas
There is a lot of advice online about storing bulbs, and some of it can be confusing. Let’s clear up a few common misconceptions about wintering canna lily bulbs.
Myth: You must wash them with a hose. As mentioned earlier, moisture is the enemy during storage. While a clean bulb is nice, a dry bulb is safer. Brushing off the soil is usually sufficient.
Myth: They need light during the winter. Canna lilies are completely dormant in the winter. They do not have leaves to process sunlight, so they should be kept in the dark. Light can actually fluctuate the temperature and encourage premature sprouting.
Myth: You should use airtight plastic bags. Airtight containers are a recipe for disaster. Rhizomes are living things and need a tiny amount of air circulation. If you use plastic bins, leave the lid slightly ajar or drill a few small holes in the sides to let the plant "breathe."
Myth: Every canna will survive. Gardening involves nature, and nature is unpredictable. Even with perfect care, a few rhizomes may not make it through the winter. This is normal! By storing a few extra, you ensure you have plenty of plants for your spring displays.
Planning Your Garden Display
Winter is the perfect time to think about where your saved cannas will go next year. Because you took the time to label them, you can plan your color schemes with confidence.
Tall Cannas make a perfect backdrop for shorter perennials or annuals. Consider pairing orange-flowered cannas with purple salvia for a high-contrast look, or use bronze-leafed varieties to add drama to a sea of green shrubbery. Since your rhizomes will likely be larger this year, you can fill even more space in your landscape.
At Longfield Gardens, we enjoy seeing how gardeners use these tropical plants to create "staycation" vibes in their own backyards. Whether they are lining a fence or flanking a front door, cannas bring a sense of grandeur that few other plants can match.
Summary of the Wintering Process
Wintering canna lily bulbs doesn't have to be a chore. When you break it down into simple steps, it becomes a satisfying end-of-season ritual.
- Wait for the frost to blacken the leaves.
- Cut the stalks back to a few inches.
- Lift the rhizomes gently with a garden fork.
- Clean and cure them in a dry place for a few days.
- Label clearly so you know what is what in the spring.
- Store in a cool, dark place (40-50°F) in a moisture-regulating medium like peat moss.
- Check periodically for rot or shriveling.
Following these steps ensures that the investment you made in your garden continues to pay off year after year.
Conclusion
Wintering canna lily bulbs doesn't have to be a chore. By respecting the plant's need for a dormant period and providing a safe, cool environment, you are setting the stage for a spectacular summer display. These bold, beautiful plants are hardy survivors, and with just a little help from you, they will continue to thrive.
- Always wait for the first frost before digging to maximize energy storage.
- Curing the rhizomes for a few days is essential for preventing rot.
- Store bulbs in a cool, dark spot between 40°F and 50°F.
- Check your bulbs monthly and adjust moisture levels as needed.
We want your garden to be a place of beauty and relaxation. Taking a small amount of time this autumn to protect your canna lilies will reward you with a magnificent, tropical paradise next summer. Happy gardening from all of us at Longfield Gardens!
FAQ
When is the best time to dig up my canna lily bulbs?
You should wait until the first frost of autumn has turned the foliage brown or black. This frost signals the plant to move its energy into the rhizome for winter storage. Once this happens, try to dig them up within a week or two, before the ground freezes solid.
What temperature should I store my canna rhizomes at?
The ideal temperature for storing canna lily bulbs is between 40°F and 50°F. This range is cool enough to keep the plant dormant but warm enough to prevent the cells from freezing. Common storage locations include unheated basements, crawlspaces, or insulated garages.
Can I store my cannas in plastic containers?
Yes, you can use plastic containers, but they should not be airtight. Canna rhizomes need a small amount of air circulation to prevent moisture buildup and rot. If your container has a tight lid, leave it slightly cracked or drill a few small ventilation holes in the sides of the bin.
My stored canna bulbs look shriveled; are they dead?
If the rhizomes look wrinkled or feel very light, they are likely just dehydrated. As long as they aren't completely brittle or hollow, you can usually save them. Lightly mist your storage medium (like peat moss or wood shavings) with water to increase the humidity, which will help the rhizomes plump back up.