Introduction
There is nothing quite like the tropical flair that canna lilies bring to a summer garden. Their bold, oversized leaves and vibrant, torch-like flowers make every backyard feel like a private island getaway. At Longfield Gardens, we love helping gardeners achieve this lush look, especially since these plants are so easy to grow and reward you with months of color. The best part is that you do not have to buy new plants every year.
Saving canna lily bulbs is a rewarding way to preserve your favorite varieties and grow your collection over time. While these tropical beauties are tender and cannot survive freezing winters in the ground in most of the United States, the process of bringing them indoors is straightforward and highly effective. This guide is designed for home gardeners who want to keep their cannas healthy and ready for a spectacular return next spring. By following a few simple steps for digging and storage, you can ensure your garden stays beautiful year after year.
Understanding Canna Lily Dormancy
Before you start digging, it is helpful to understand how cannas grow. While we often call them "bulbs," cannas actually grow from thick, fleshy underground stems called rhizomes. These rhizomes act like a storage tank, holding all the energy the plant needs to sprout again after a period of rest.
In warm climates (USDA hardiness zones 8 to 11), cannas can often stay in the ground all year. However, for the rest of us, winter temperatures will freeze the water inside those fleshy rhizomes, causing them to turn to mush. Saving canna lily bulbs is simply a matter of helping the plant enter a safe, dry dormancy indoors before the deep freeze sets in. For help identifying your region, see the hardiness zone map.
Dormancy is a natural part of the plant’s life cycle. Just as we sleep to recharge, the canna lily needs a cool, dark rest period to prepare for the explosive growth of the following summer. When you lift and store them, you are acting as a guardian for that energy.
When to Dig Up Your Cannas
Timing is everything when it comes to saving canna lily bulbs. 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 solid.
The most reliable signal for digging is the first "blackening frost." This occurs when the overnight temperature drops just enough to kill the foliage. You will notice the lush green or bronze leaves suddenly turn dark brown or black and wilt. This is not a sign of failure; it is actually a helpful trigger. Once the leaves die back, the plant stops sending energy upward and settles into its rhizomes for the season.
If you live in a region where a hard frost comes very late, you can still dig them up in late autumn. Aim for a time when the days are consistently cool and the plant’s growth has clearly slowed down.
Key Takeaway: The best time to dig is right after the first light frost has blackened the leaves, but before the ground itself has frozen.
Preparing the Plants for Digging
Once the frost has done its work, the first step is to clear away the spent foliage. This makes the digging process much easier and keeps your storage area cleaner.
Use a sharp pair of garden shears or a lopper to cut the stalks down. You should leave about 2 to 4 inches of the stem attached to the rhizome. This small "handle" is useful for moving the rhizomes around and helps you remember which side is up when it comes time to replant in the spring.
It is a good idea to clear away any mulch or garden debris from around the base of the plants at this stage. This gives you a clear view of where the clumps begin and end, which helps prevent accidental damage during the digging process.
What to do next:
- Identify the plants you want to save.
- Wait for the first frost to blacken the leaves.
- Cut the stems down to a few inches above the soil line.
- Clear the area of any extra mulch or weeds.
How to Dig Canna Lily Rhizomes
Digging up canna rhizomes is a gentle process. Because the rhizomes are fleshy and full of moisture, they can be easily nicked or bruised. A damaged rhizome is more prone to rot during the winter, so a slow and steady approach is best.
Instead of a shovel, we recommend using a garden fork. A fork allows you to loosen the soil without the sharp, flat blade of a spade cutting through the middle of a large clump. Start your digging about 10 to 12 inches away from the main stem. This ensures you are well outside the "impact zone" where the new rhizomes have grown during the summer.
Gently pry upward from several sides of the plant. You want to lift the entire root ball out as one large mass. Canna rhizomes often grow in a circular pattern, expanding outward from the original point where they were planted. Once the soil is loose, you can usually lift the clump out by the stem handles you left behind.
Cleaning and Curing
After the rhizomes are out of the ground, they need a little bit of "spa time" before they go into storage. This stage is called curing, and it is vital for preventing mold and rot. For additional guidance, see this canna planting and care guide.
First, shake off the excess soil. You do not need to get them perfectly clean. In fact, many gardeners prefer to leave a little bit of dry soil on the rhizomes as a protective layer. If the soil is very wet and sticky, you can use your hands to gently brush it away. Avoid using a high-pressure hose to wash them, as excess moisture is the enemy of successful winter storage.
Once the bulk of the soil is gone, lay the rhizomes out in a single layer in a dry, frost-free area. A garage, a shed, or even a covered porch works well. Let them sit for two to three days. During this time, the outer "skin" of the rhizome will toughen up slightly. This process, known as curing, helps seal in the internal moisture the plant needs to survive while keeping out the fungi that cause decay.
Inspecting for Quality
While your rhizomes are curing, take a moment to look them over. Not every rhizome is a candidate for storage. You are looking for pieces that feel firm and heavy for their size.
If you find any parts that are soft, mushy, or have an unpleasant odor, use a clean knife to trim those sections away. If a whole clump seems shriveled or excessively light, it may have dried out too much or suffered from a summer pest. It is better to store only the healthiest, most robust pieces. This ensures that when spring arrives, you are starting with high-quality stock that is ready to perform.
Key Takeaway: Only store rhizomes that are firm and free of soft spots. Taking a few minutes to inspect your harvest now will save a lot of disappointment in the spring.
Choosing the Right Storage Container
The goal of storage is to keep the rhizomes in a "Goldilocks" environment: not too cold (which freezes them), not too warm (which makes them sprout), and not too wet (which causes rot).
There are several ways to house your cannas for the winter. The most common methods include:
Cardboard Boxes
Cardboard is an excellent material because it "breathes." It allows for minimal air exchange while still protecting the rhizomes from light and temperature fluctuations. Line the bottom of the box with a few sheets of newspaper for extra insulation.
Plastic Bins
If you use plastic storage totes, do not snap the lid on tight. Without airflow, moisture will build up inside and cause the rhizomes to rot within weeks. If you prefer plastic, keep the lid cracked or drill several small holes in the sides to allow air to circulate.
Paper Bags
For smaller collections or individual varieties, heavy-duty brown paper bags are a great choice. You can place several rhizomes in a bag, add some packing material, and tuck them away on a shelf. This is also a great way to keep different colors or varieties labeled so you don't mix them up.
Packing Materials for Moisture Control
Saving canna lily bulbs successfully often depends on what you pack them in. While the rhizomes shouldn't be wet, they shouldn't be bone-dry either. A packing medium helps regulate the humidity around the plant.
- Peat Moss: This is a classic choice. It is naturally acidic, which can help inhibit fungal growth, and it holds just enough moisture to prevent shriveling.
- Vermiculite or Perlite: These lightweight minerals are excellent for drainage and airflow. They are very clean and easy to handle.
- Wood Shavings: The kind sold for pet bedding (usually cedar or pine) works very well. It smells nice and provides a dry, airy cushion.
- Dry Sand: While heavy, sand is a traditional storage medium that does a great job of keeping temperatures stable.
To pack them, place a few inches of your chosen material in the bottom of your container. Lay the rhizomes in a single layer so they aren't touching each other. Then, cover them with more material. You can stack them in layers, but make sure there is plenty of packing medium between each piece.
Finding the Perfect Storage Location
The environment where you keep your containers is just as important as how you pack them. Cannas prefer a temperature range between 40°F and 50°F. The same temperature range is recommended in this guide to curing and storing canna rhizomes.
- Unheated Basements: Often the most consistent spot in a home. Stay away from the furnace or water heater.
- Crawl Spaces: These stay cool and dark, though you should check for dampness.
- Attached Garages: This can work, but be careful. If your garage frequently drops below freezing, your cannas will not survive. Place the boxes on a shelf or a wooden pallet rather than directly on the cold concrete floor.
Avoid storing them in a living area of the house, as the indoor heating will dry them out too quickly or trick the plants into thinking it is time to grow.
Winter Storage Checklist:
- Choose a breathable container like a cardboard box.
- Use a dry packing medium like peat moss or wood shavings.
- Keep the rhizomes from touching one another.
- Store in a dark, cool spot (40-50°F).
- Label every box with the variety name and the date.
Monitoring Your Rhizomes Through Winter
Saving canna lily bulbs is not a "set it and forget it" task. It is wise to check on your "guests" once a month. This small effort can prevent a minor issue from becoming a total loss.
When you check them, feel a few of the rhizomes. If they feel firm, everything is going well. If you notice a rhizome has developed a soft spot or mold, remove it immediately so it doesn't spread to the others.
If the rhizomes appear shriveled or feel very light, they are losing too much moisture. You can use a spray bottle to very lightly mist the packing material. Do not soak it; just a tiny bit of humidity is enough to stop the shriveling. Conversely, if you see condensation on the inside of the box or the packing material feels damp, leave the lid off for a few days to let it dry out.
Dividing Your Cannas
One of the most exciting parts of saving canna lily bulbs is seeing how much they have grown. A single rhizome planted in May can turn into a massive clump by October. Winter or early spring is the perfect time to divide these clumps.
Look for the "eyes" on the rhizome. These are small, rounded bumps where next year’s stems will emerge. To divide a clump, use a clean, sharp knife to cut it into smaller sections. Each new piece should have at least two or three healthy eyes and a good amount of the fleshy root attached.
Allow the cut ends of the divided rhizomes to dry and "callus" over for a day or two before you put them back in storage or prepare them for planting. This simple multiplication means you can have more plants for your own garden or plenty of extras to share with friends and neighbors.
Getting a Head Start in Spring
As the days get longer and the ground begins to thaw, you might see your stored cannas starting to wake up. Small white or pink sprouts may appear at the eyes. This is a sign that the plants are ready for the new season.
In most parts of the US, cannas shouldn't go into the ground until the soil is warm—usually around the same time you would plant tomatoes. However, if you want flowers earlier in the summer, you can "start" them indoors about 4 to 6 weeks before the last frost. For container-growing ideas, see this guide to growing canna bulbs in pots.
Plant the rhizomes in large pots with standard potting soil. Keep them in a warm, sunny window or under grow lights. By the time the weather is warm enough to move them outside, you will have established plants that are several inches tall. This gives you a significant head start on the blooming season.
Common Canna Varieties for Success
At Longfield Gardens, we offer a wide range of cannas that are specifically chosen for their beauty and vigor. When you are saving your bulbs, it helps to know which types you have so you can plan your landscape accordingly. You can browse the assorted canna collection for a mix of varieties.
- Tall Varieties: These can reach 4 to 6 feet in height. They are perfect for the back of a flower bed or for creating a temporary privacy screen. Varieties like 'The President' (red) or 'Richard Wallace' (yellow) are classic choices.
- Dwarf Varieties: If you have a smaller garden or prefer growing in containers, dwarf cannas are ideal. They usually stay under 3 feet tall but still produce full-sized, gorgeous flowers.
- Variegated Foliage: Some cannas are grown as much for their leaves as their flowers. 'Pretoria' (also known as 'Bengal Tiger') features stunning yellow and green striped leaves, while 'Tropicanna' offers bold orange, red, and purple tones.
Keeping track of which is which during the storage process is key. Use a waterproof marker to write the variety directly on the "stem handle" or use a tag attached with a bit of twine.
Simple Steps for Success
While the process of saving canna lily bulbs might seem detailed, it really comes down to a few basic principles that we follow at Longfield Gardens. If you keep the plants dry, cool, and dark, they will almost always reward you with a beautiful performance the following year.
Gardening is about observation and enjoying the rhythm of the seasons. Moving your cannas indoors for the winter is a great way to stay connected to your garden even when the ground is covered in snow. It turns a one-season plant into a lifelong companion for your landscape.
Key Takeaway: Success with cannas comes from mimicking their natural dormancy. Cool temperatures, low light, and controlled moisture are the secrets to healthy rhizomes.
Conclusion
Saving your canna lily bulbs is a simple and satisfying way to ensure your garden remains a tropical paradise year after year. By digging them up after the first frost, curing them properly, and storing them in a cool, dark place, you protect the investment you’ve made in your outdoor space. It is a wonderful feeling to open your storage boxes in the spring and find firm, healthy rhizomes ready to start the cycle all over again.
At Longfield Gardens, we stand behind the quality of our plants and want to see your garden thrive. We work with the best growers to provide you with healthy, true-to-variety rhizomes that are ready to perform. You can learn more about the company through the Longfield Gardens guarantee and About Us page. Whether you are a seasoned gardener or just starting your first tropical-inspired bed, the process of overwintering is a great skill to have in your gardening toolkit.
- Wait for the frost to trigger dormancy.
- Dig carefully and cure for a few days.
- Store in a cool, dry, and dark location.
- Check monthly for moisture levels.
Ready to expand your collection? Explore the assorted canna rhizome collection and other summer-blooming favorites to add even more color and height to your garden next season.
FAQ
Can I leave my canna lilies in the ground if I mulch them heavily?
If you live in USDA zone 7 or colder, mulching is usually not enough to protect the rhizomes from a deep ground freeze. In these regions, it is best to dig them up and store them indoors to guarantee they survive. In zones 8 and warmer, a thick layer of mulch is often sufficient to keep them safe through the winter.
Should I wash the dirt off the canna rhizomes with a hose?
It is generally better to avoid washing them with water. Excess moisture can get trapped in the nooks and crannies of the rhizome, which significantly increases the risk of rot during storage. Instead, let the soil dry out slightly and then gently brush it off with your hands or a soft brush.
My stored canna rhizomes feel a little soft. Are they still okay?
If the rhizome is only slightly flexible, it might just be a bit dehydrated; you can mist it lightly with water. However, if it feels mushy, looks slimy, or has a bad smell, it has started to rot. You should immediately cut away any soft sections with a clean knife or discard the piece entirely to protect your other rhizomes.
When exactly should I plant my saved cannas back outside?
Cannas are tropical plants that love heat. Wait until the danger of frost has completely passed and the soil has warmed up to at least 60°F. Planting them too early in cold, wet soil can cause the rhizomes to rot before they have a chance to sprout. A good rule of thumb is to plant them at the same time you would put out your summer annuals or vegetable starts. For additional planting guidance, see the spring canna planting guide.
