Table of Contents
- Introduction
- Understanding Canna Rhizomes
- When to Begin the Storage Process
- How to Dig Up Your Canna Rhizomes
- Cleaning and Curing
- Selecting the Right Storage Medium
- Ideal Storage Conditions
- Mid-Winter Maintenance
- Special Case: Cannas in Containers
- Preparing for Spring Replanting
- Common Mistakes to Avoid
- Conclusion
- FAQ
Introduction
Cannas bring a bold, tropical flair to the garden that is hard to match. After a summer filled with vibrant blooms and lush foliage, it is only natural to want to keep that beauty going for the following year. While these plants love the heat, they are not fans of freezing temperatures. We at Longfield Gardens want to help you preserve your favorite cannas so they can return even stronger next season.
This guide will walk you through the simple steps of digging, cleaning, and storing your plants. Storing canna lily bulbs for winter is a straightforward process that rewards you with bigger, better displays each year. If you enjoy a mix of sizes and colors, the Assorted Cannas collection is an easy place to start. By following a few basic principles, you can ensure your garden remains a spectacular retreat without needing to start from scratch every spring.
Understanding Canna Rhizomes
Before we get into the "how," it helps to know what we are actually storing. Although most gardeners refer to them as bulbs, cannas actually grow from rhizomes. A rhizome is a thick, fleshy underground stem that stores energy for the plant.
During the summer, the plant uses this energy to produce those iconic leaves and flowers. As the season winds down, the plant begins moving energy back into the rhizome. This is why the timing of your harvest is so important. You want to give the plant as much time as possible to "recharge" before you tuck it away for the winter. For a broader overview of planting, growing, and overwintering, see All About Cannas.
When to Begin the Storage Process
The best time for storing canna lily bulbs for winter depends largely on your local weather. Nature usually provides a very clear signal for when it is time to act.
The First Frost Signal
For most gardeners, the arrival of the first light frost is the perfect cue. A light frost will usually turn the canna’s lush green or bronze foliage to a dark brown or black. While this might look a bit sad at first, it is actually a helpful part of the process. This "frost-kill" tells the plant to stop growing and enter its dormant state.
You do not need to panic the moment the temperature drops. The rhizomes are safely insulated under the soil. However, you should aim to have them out of the ground before a hard freeze occurs. A hard freeze—where the ground itself begins to harden—can damage the tender rhizomes.
Monitoring Your USDA Zone
Your approach to winter care will vary depending on where you live. Monitoring your USDA Zone will help you decide.
- Zones 8 and warmer: In these mild climates, cannas can often stay in the ground all year. You simply cut the foliage back and add a thick layer of mulch for protection.
- Zone 7: This is the "swing" zone. In many years, cannas survive with heavy mulching, but a particularly cold winter can be risky. Many gardeners in this zone choose to dig up their favorites just to be safe.
- Zones 6 and colder: In these regions, the ground will freeze deep enough to kill the rhizomes. Digging and storing them indoors is essential for survival.
Key Takeaway: Wait for the first light frost to blacken the leaves. This serves as nature’s signal that the rhizomes are ready for dormancy and have stored maximum energy for next year.
How to Dig Up Your Canna Rhizomes
Digging is the first hands-on step in storing canna lily bulbs for winter. The goal is to lift the rhizomes without causing physical damage.
Preparation
Start by cutting the stalks down. Use a clean pair of garden shears to cut the foliage back to about 4 to 6 inches above the soil line. Leaving a bit of the "handle" makes the rhizomes easier to manage and helps you keep track of which end is up.
Lifting the Clump
Cannas can grow quite large over a single season. Tall Cannas are a good reminder of how much space they can take.
- Give them space: Use a garden fork or a sturdy shovel. Start digging about 12 inches away from the base of the stalks. This prevents you from accidentally slicing through the fleshy rhizomes.
- Loosen the soil: Circle the plant, prying upward gently from different angles.
- Lift: Once the soil is loose, lift the entire clump out of the ground. Don't be surprised if the clump is heavy; they can hold a significant amount of moisture and soil.
Cleaning and Curing
Once the rhizomes are out of the ground, they need a little bit of preparation before they go into storage.
Removing Excess Soil
Gently shake the clump to remove large chunks of soil. You can use your hands to brush away the rest. Some gardeners prefer to rinse the rhizomes with a garden hose to get them completely clean. This is a great way to spot any hidden pests or signs of rot. If you do wash them, ensure they have plenty of time to dry completely afterward.
The Curing Phase
Curing is one of the most important steps in storing canna lily bulbs for winter. This is a simple air-drying process that allows the outer "skin" of the rhizome to toughen up, which helps prevent rot.
Place your cleaned rhizomes in a well-ventilated area that is out of direct sunlight. A garage, a covered porch, or a garden shed works perfectly. Let them sit for about 3 to 7 days. You want the surface to feel dry to the touch and any remaining bits of soil to be crumbly.
To Divide or Not to Divide?
When you lift a large clump, you will see how the rhizomes have branched out. You can choose to divide them now or wait until spring. If you want a mid-size option for next year, Medium Cannas are a practical choice.
- Fall Division: If you divide now, you save storage space. Use a sharp, clean knife and ensure every piece has at least one "eye" (a small bump where new growth will emerge).
- Spring Division: Many gardeners prefer to wait until spring. The "eyes" are much easier to see once the plant starts to wake up, and a larger clump is sometimes more resilient against drying out over the winter.
What to do next:
- Cut stalks to 4-6 inches.
- Dig wide to avoid damaging the fleshy roots.
- Shake off loose dirt or rinse gently.
- Air-dry (cure) in a protected spot for up to a week.
Selecting the Right Storage Medium
You cannot simply toss cannas on a shelf and expect them to thrive. They need a storage medium that maintains a very delicate balance: they must stay dry enough to prevent rot, but moist enough so they don't turn into shriveled, hard husks.
Popular Storage Options
- Peat Moss: This is the gold standard for many gardeners. It is sterile and does a great job of regulating moisture.
- Vermiculite or Perlite: These provide excellent aeration and are very lightweight.
- Wood Shavings or Sawdust: Common and inexpensive, but ensure they are not from treated lumber.
- Newspaper: Wrapping individual rhizomes in newspaper is a low-cost method that works well if your storage area has consistent humidity.
The Best Containers
Cardboard boxes, plastic bins (with the lids left slightly ajar), or even breathable mesh bags are all good choices. Avoid airtight plastic bags or sealed containers, as these trap moisture and almost always lead to mold and rot.
Ideal Storage Conditions
Where you put your cannas is just as important as how you pack them. They need a "Goldilocks" environment—not too hot, not too cold.
Temperature
The ideal temperature range is between 40°F and 50°F.
- If it’s too cold: If the temperature drops below freezing, the water inside the rhizomes will expand and destroy the plant cells, leading to a mushy, dead plant.
- If it’s too warm: If the temperature stays above 60°F, the cannas may think it is spring and try to start growing in the dark, which exhausts their energy.
Locations to Consider
An unheated basement, a crawl space, or a cool closet are usually the best spots. If you use a garage, make sure it is attached to the house or insulated enough that it won't drop below freezing during a winter storm.
Mid-Winter Maintenance
Storing canna lily bulbs for winter is not a "set it and forget it" task. Checking on your plants once a month can make the difference between success and loss.
Checking for Rot
If you see a rhizome that has become soft, slimy, or has a foul odor, remove it immediately. Rot can spread quickly from one piece to another. If only a small tip is soft, you can sometimes cut it back to healthy tissue and let it dry out.
Managing Desiccation
If the rhizomes look very shriveled or feel extremely light, they may be getting too dry. You can lightly mist the storage medium with a spray bottle. You aren't looking to make it wet—just slightly damp to the touch.
Special Case: Cannas in Containers
If you grow your cannas in large pots, you have a "short cut" available. Short Cannas are especially handy in containers.
Once the frost has hit the foliage, cut the stalks down to soil level. Instead of digging the rhizomes out, simply move the entire container into a cool, frost-free location. The soil in the pot acts as a natural insulator and storage medium. In the spring, you can pull the clump out to divide it and refresh the soil before putting the pot back outside.
Preparing for Spring Replanting
As winter fades and the ground begins to warm, it is time to think about bringing your cannas out of hibernation.
Waking Them Up
About 4 to 6 weeks before the last expected frost, you can move your storage boxes to a slightly warmer area. This gentle increase in temperature encourages the "eyes" to begin swelling.
If you want an even earlier head start, you can plant the rhizomes in pots indoors. Place them in a sunny window or under grow lights. By the time the weather is consistently warm outside, you will have established plants ready to go into the ground.
The Transition
Wait until the soil has warmed to at least 60°F before planting outdoors. Cannas are tropical at heart; they won't do much in cold, damp spring soil. Patience pays off here. When the weather is right, they will grow rapidly and reward you with a stunning summer display.
Common Mistakes to Avoid
While storing canna lily bulbs for winter is simple, avoiding these common pitfalls will ensure a much higher success rate.
Don't Store Them Wet
Putting damp rhizomes into a plastic bin is a recipe for disaster. The lack of airflow combined with moisture leads to fungal growth. Always ensure the "curing" phase is complete and the surface of the rhizome is dry.
Don't Forget the Labels
It is incredibly easy to forget which canna is which when they are just brown rhizomes in a box. Use a permanent marker to write the variety name directly on the rhizome or the newspaper wrap. This helps you plan your garden colors more effectively in the spring.
Avoid Drafty or Heating Vent Areas
Placing your storage box right next to a furnace or a drafty door can cause the rhizomes to dry out too quickly or experience temperature swings that break their dormancy.
Simple Storage Checklist:
- Ensure rhizomes are dry to the touch.
- Use a breathable medium like peat moss.
- Keep temperatures between 40°F and 50°F.
- Check once a month for soft spots.
Conclusion
Successfully storing canna lily bulbs for winter is a rewarding skill that allows you to build a more beautiful garden year after year. It transforms a one-season plant into a long-term investment. By following nature's cues and providing a cool, dry resting place, you ensure that your tropical favorites return with even more vigor.
At Longfield Gardens, we believe that these simple steps make gardening more enjoyable and accessible for everyone. Once you have mastered the winter storage process, you can confidently expand your collection with Canna Tall Tropicanna.
- Wait for the first frost to signal dormancy.
- Cure the rhizomes for several days before packing.
- Maintain a cool, consistent temperature throughout the winter.
- Replant only after the soil has warmed in late spring.
Keeping cannas over the winter is a simple way to enjoy bigger and better blooms every year. It’s a small amount of effort that pays off with a stunning, tropical garden every summer.
We look forward to seeing your garden grow! For more tips on caring for your favorite plants, visit our gardening guides.
FAQ
When is the best time to dig up my canna lily rhizomes?
The best time is shortly after the first light frost in the fall. This frost will turn the foliage dark and signal the plant to go dormant, but the ground will still be soft enough for easy digging. Aim to have them out of the ground before a deep, hard freeze.
Can I store canna rhizomes in my unheated garage?
Yes, as long as the garage stays above freezing. Ideally, the temperature should remain between 40°F and 50°F. If your garage gets colder than 32°F, the rhizomes may freeze and die, so you might need to move them to a basement or crawl space. If you need help timing shipments by climate, see our Shipping Information.
Do I need to wash the dirt off before storing them?
While not strictly necessary, removing excess soil helps you inspect the rhizomes for pests or rot. If you do wash them with a hose, it is vital to let them "cure" or air-dry for several days until the surface is completely dry before putting them in a storage container.
What should I do if my rhizomes look shriveled in the middle of winter?
If the rhizomes look very wrinkled or feel light and "corky," they are losing too much moisture. Lightly mist the storage medium (like peat moss or newspaper) with a small amount of water to increase the humidity. Be careful not to make the medium wet, as this can cause rot. If you still have questions, please Contact Us.