Table of Contents
- Introduction
- Understanding Why We Lift Canna Rhizomes
- When to Begin Lifting Canna Lily Bulbs
- Essential Tools for a Successful Lift
- A Step-by-Step Guide to Digging Cannas
- The Importance of Curing
- Dividing Rhizomes During the Lift
- Choosing the Best Storage Medium
- Finding the Right Temperature
- Winter Check-ins and Maintenance
- Preparing for Spring Replanting
- Conclusion
- FAQ
Introduction
Cannas bring a vibrant, tropical energy to the garden with their oversized leaves and brilliant, exotic blooms. Whether you grow them for their sunset-colored flowers or their striking variegated foliage, these plants are consistent showstoppers. At Longfield Gardens, we love how easily these tropical beauties transform a standard backyard into a lush summer retreat.
Lifting canna lily bulbs—which are technically called rhizomes—is a simple end-of-season task that allows you to enjoy these plants year after year. This process is essential for gardeners in cooler climates where the ground freezes during the winter months. By following a few straightforward steps, you can keep your favorite varieties safe and dormant until the warmth of spring returns.
This guide is designed to help you confidently dig, clean, and store your cannas for the winter. We will cover the ideal timing for lifting, the best storage conditions, and how to ensure your plants return even stronger next season. Shop Cannas is a good place to start if you want to plan ahead for spring.
Understanding Why We Lift Canna Rhizomes
Cannas are native to tropical and subtropical regions. This means they thrive in heat and humidity but have very little natural defense against freezing temperatures. In the United States, cannas are generally considered hardy in USDA zones 9 and 10. In these warm areas, the rhizomes can stay in the ground all year long with just a layer of mulch for protection.
For gardeners in zones 8 and colder, the winter brings a risk of the ground freezing deep enough to damage the plant's energy stores. The "bulb" of a canna is actually a rhizome, which is a thick, fleshy underground stem. These rhizomes act like a battery, storing the energy the plant needs to push out new growth in the spring. If the rhizome freezes, the cells inside rupture, and the plant will not survive.
Lifting is the process of digging these rhizomes up and moving them to a frost-free environment. This practice turns a tender perennial into a lifelong garden companion. It also gives you a chance to inspect the health of your plants and prepare them for division, which is the best way to expand your garden for free.
When to Begin Lifting Canna Lily Bulbs
Timing is one of the most important factors when it comes to successfully overwintering cannas. You want to leave the plants in the ground as long as possible so they can store maximum energy. During the late summer and early fall, cannas are busy moving sugars from their leaves down into the rhizomes.
The best indicator that it is time to lift is the first frost of the season. You will notice that a light frost turns the lush green or burgundy leaves to a dark brown or black. While this might look disappointing, it is actually a helpful signal. The frost tells the plant that it is time to go dormant.
Wait until the foliage has been hit by frost before you start digging. However, do not wait so long that the ground begins to freeze hard. A "blackening frost" is perfect. If you live in an area where the transition from autumn to deep winter is very fast, keep a close eye on the forecast. You want to complete the lifting process while the soil is still workable and relatively dry.
What to do next:
- Monitor your local weather forecast for the first "killing frost."
- Prepare your tools, such as a garden fork, shears, and labels.
- Clear a space in a cool, dry area like a basement or insulated garage for the curing process.
Essential Tools for a Successful Lift
You do not need specialized machinery to lift cannas, but using the right hand tools makes the job much easier. A sturdy garden fork is often better than a shovel. The tines of a fork allow you to loosen the soil around the rhizomes without accidentally slicing through them. Since canna rhizomes can grow quite large and spread horizontally, a shovel often does more damage than a fork.
You will also need a sharp pair of bypass pruners or garden shears. These are used to remove the frost-damaged stalks. Clean tools are important to prevent the spread of any soil-borne issues, so give your equipment a quick wipe before you head out to the garden.
Finally, have some labeling materials ready. Many canna varieties look identical once they are reduced to a bare rhizome. Using waterproof tags or writing the variety name directly on the rhizome with a permanent marker ensures you know exactly what you are planting next spring.
A Step-by-Step Guide to Digging Cannas
Lifting canna lily bulbs is a physical task, but it is very straightforward once you get moving. Follow these steps to ensure the rhizomes stay intact and healthy.
1. Cut Back the Foliage
Start by using your pruners to cut the stalks down. You should leave about 2 to 4 inches of stem protruding from the soil. This "handle" serves two purposes: it makes the rhizomes easier to grab, and it helps you identify which side is "up" when it comes time to replant. Avoid cutting the stems all the way flush with the rhizome, as this can create an entry point for moisture or decay during storage.
2. Loosen the Soil
Position your garden fork about 6 to 10 inches away from the base of the stems. Canna rhizomes grow outward horizontally, so you want to give the plant plenty of space. Push the fork deep into the soil and gently rock it back and forth to loosen the earth. Work your way in a circle around the entire clump.
3. Lift the Root Mass
Once the soil is loose, use the fork to pry the entire root mass upward. You may be surprised by how heavy a healthy canna clump can be. If the clump is too large to lift at once, you can gently use the fork to break it into smaller, more manageable sections. Lift the mass out of the ground and set it on the soil surface or a tarp.
4. Remove Excess Soil
Gently shake the clump to remove large chunks of dirt. You can use your hands to brush away loose soil, but avoid being too aggressive. The "skin" of a fresh canna rhizome is relatively soft and can be easily bruised or nicked. You do not need to get the rhizomes perfectly clean at this stage; a little bit of clinging soil is fine.
Key Takeaway: Always dig wider than you think you need to. Canna rhizomes are vigorous growers and often spread further from the center than other summer bulbs. Digging a wide circle prevents accidental damage to the growing points.
The Importance of Curing
Before you put your cannas into their winter storage containers, they must go through a process called curing. Curing is simply allowing the rhizomes to air-dry for a short period. This helps the outer surface toughen up and allows any wounds from the digging process to callous over.
Place your lifted rhizomes in a protected, frost-free area with good air circulation. A porch, a shed, or a garage floor works well. Spread them out in a single layer so they are not touching. Avoid placing them in direct sunlight, as this can cause them to dry out too quickly or "cook" the internal tissue.
The curing process usually takes between 2 and 7 days, depending on the humidity and temperature. You will know they are ready when the outer skin feels dry to the touch and any remaining soil has turned into a dry powder that easily brushes off. Do not wash your rhizomes with a hose. Adding excess water at this stage increases the risk of mold and rot during the long winter months.
Dividing Rhizomes During the Lift
Lifting season is the perfect time to divide your cannas. Because these plants grow via underground stems, they naturally become crowded over time. Dividing them every year or two keeps the plants healthy and gives you more bulbs to plant elsewhere or share with friends.
Look for natural "joints" in the rhizome clump. A healthy division should have at least two or three "eyes." These eyes are small, rounded bumps or points where the new stems will emerge in the spring. You can often pull the rhizomes apart by hand. If the clump is very dense, use a clean, sharp knife to make precise cuts.
If you make any fresh cuts during division, ensure those pieces get extra time to cure. The cut surface needs to be completely dry and hard before it goes into storage. This "scabbing over" is the plant's natural defense against decay.
Choosing the Best Storage Medium
Once your canna rhizomes are cured and labeled, they need a cozy place to spend the winter. The goal is to keep them dormant—not so wet that they rot, but not so dry that they shrivel up like a raisin.
We recommend using a breathable storage medium. Common choices include:
- Peat Moss: This is a classic choice because it holds just enough moisture to prevent shriveling while allowing air to circulate.
- Vermiculite or Perlite: These lightweight minerals are excellent for moisture regulation.
- Wood Shavings: Cedar or pine shavings (the kind used for pet bedding) are affordable and naturally resistant to mold.
- Newspaper or Paper Bags: In more humid basements, simply wrapping rhizomes in several layers of newspaper can be sufficient.
Avoid using airtight plastic containers or sealed plastic bags. These trap moisture and almost always lead to rot. Cardboard boxes, wooden crates, or breathable burlap bags are much better options for housing your cannas for the winter.
Finding the Right Temperature
The temperature of your storage area is the final piece of the overwintering puzzle. Cannas prefer a spot that is dark, cool, and dry. The ideal temperature range is between 45°F and 50°F.
If the storage area is too warm (above 60°F), the rhizomes may think it is spring and start to sprout prematurely. If they grow long, pale shoots in the dark, they will waste the energy they need for the actual growing season. If the area is too cold (below 40°F), you risk the rhizomes getting chilled or frozen, which will kill them.
Basements, crawl spaces, and insulated garages are usually the best spots. Avoid areas near furnaces, water heaters, or large windows where temperatures can fluctuate wildly throughout the day and night.
Winter Check-ins and Maintenance
Overwintering is not a "set it and forget it" task. We recommend checking on your stored cannas about once a month. This small effort can save your entire collection if something goes wrong.
During your check-in, look for two things:
- Signs of Rot: If a rhizome feels mushy or has a foul smell, remove it immediately. Rot can spread quickly to healthy rhizomes if they are touching.
- Excessive Shriveling: If the rhizomes look very wrinkled or feel light and hollow, they are losing too much moisture. You can lightly mist the storage medium (the peat moss or shavings) with a spray bottle to add a tiny bit of humidity. Do not soak them; just a hint of dampness is enough to stop the shriveling.
Most gardeners find that their cannas stay perfectly healthy with very little intervention. By keeping the environment stable and checking in occasionally, you ensure that your rhizomes stay plump and ready for action.
Preparing for Spring Replanting
As the days get longer and the ground begins to thaw, your cannas will naturally start to wake up. You may see small colorful nubs—the eyes—starting to swell. This is an exciting sign that your lifting and storage efforts were successful!
In most parts of the US, you can begin replanting cannas outdoors once the soil has warmed to about 65°F and all danger of frost has passed. Because we ship our products from our facility in Lakewood, New Jersey, we always time our deliveries based on your local planting zone. Shipping information helps explain how that timing works.
If you want an even earlier start, you can "wake up" your stored cannas by planting them in pots indoors about 4 to 6 weeks before the last frost. This gives them a head start, resulting in larger plants and earlier blooms once they are moved to the garden.
What to do next:
- In late winter, move your storage boxes to a slightly warmer spot to encourage the "eyes" to wake up.
- Check your local extension office for the average last frost date in your area.
- Plan your garden layout, keeping in mind that cannas love full sun and plenty of water.
Conclusion
Lifting canna lily bulbs is one of those simple gardening tasks that offers a massive reward. By taking a little time each autumn to dig and store these tropical treasures, you can build a stunning, mature garden that grows more impressive every year. At Longfield Gardens, we believe that gardening should be a source of joy and beauty, and preserving your favorite plants is a wonderful part of that journey.
- Wait for the first frost to signal dormancy before you begin digging.
- Cure the rhizomes in a dry, protected area for a few days to toughen the skin.
- Store in a breathable medium like peat moss or wood shavings.
- Maintain a cool, consistent temperature between 45°F and 50°F.
Successful overwintering is all about working with the plant's natural cycle. With these steps, you can look forward to another season of lush, tropical foliage and vibrant flowers. For more high-quality summer bulbs and gardening inspiration, we invite you to explore our selection and plan your most beautiful garden yet with us at Longfield Gardens.
FAQ
When is the best time to lift cannas?
The best time to lift your cannas is shortly after the first "killing frost" of autumn. You will know the time is right when the leaves turn brown or black from the cold. This frost signals the plant to go dormant, moving its energy into the rhizome for winter storage.
Do I need to wash the dirt off my canna rhizomes before storing them?
It is actually better to avoid washing them with a hose. Excess water can lead to mold or rot during storage. Instead, allow the rhizomes to dry (cure) for a few days, and then gently brush off any large clumps of dry soil with your hands.
Where is the best place to store canna bulbs over the winter?
A cool, dark, and dry location is ideal. Most gardeners find success in a basement, an insulated garage, or a crawl space where temperatures stay between 45°F and 50°F. Ensure the spot is frost-free but not near a heat source like a furnace.
Can I leave my canna lilies in the ground in Zone 7?
In Zone 7, cannas are on the edge of hardiness. While they sometimes survive mild winters with a thick layer of mulch (6-12 inches of straw or leaves), lifting them is the only way to ensure they survive a particularly cold snap. For guaranteed results, we recommend lifting them in Zone 7 and colder.