Table of Contents
- Introduction
- Why Digging Canna Bulbs is Important
- When Is the Best Time to Dig?
- Identifying Your Garden Zone
- Essential Tools for Digging Cannas
- Step-by-Step Guide: How to Dig Canna Bulbs
- Preparing the Rhizomes for Storage
- Best Methods for Winter Storage
- Managing Container-Grown Cannas
- Checking Your Cannas During the Winter
- Planning for Spring Replanting
- Simple Tips for Success
- Conclusion
- FAQ
Introduction
One of the most rewarding parts of gardening is watching a small plant transform into a towering tropical masterpiece. Cannas bring a sense of drama and vibrant color to any garden with their bold leaves and striking flowers. As the growing season winds down, you have the wonderful opportunity to save these plants so they can return even bigger and better next year.
At Longfield Gardens, we want to help you enjoy your favorite canna varieties for many seasons to come. Learning how to dig canna bulbs is a simple and satisfying fall ritual that ensures your garden remains a lush sanctuary. This guide is for any gardener who wants to preserve their tropical treasures through the cold winter months.
We will walk you through the timing, the tools, and the best techniques for lifting and storing your cannas. With just a little bit of effort in the fall, you can look forward to a spectacular display when the warm weather returns. Understanding the right way to dig and store these plants is the key to maintaining a beautiful and sustainable landscape.
Why Digging Canna Bulbs is Important
Cannas are tropical plants that thrive in heat and humidity. In their native environments, they grow year-round without a break. However, in most parts of the United States, winter temperatures drop far below what these plants can handle. While we often call them bulbs, cannas actually grow from thick, fleshy underground stems called rhizomes. These rhizomes act as energy storage units for the plant.
If left in freezing soil, the water inside the rhizomes will freeze, causing the cell walls to burst. This leads to the plant rotting once the ground thaws. By digging them up, you are essentially hitting the "pause" button on their growth. You provide them with a safe, dormant environment where they can rest until the spring sun warms the earth again.
Saving your own cannas is also a great way to expand your garden for free. During a single growing season, one small rhizome can grow into a large clump with several new "eyes" or growing points. When you dig them up, you can divide these clumps and turn one plant into three or four. This process allows you to fill more of your garden beds with canna varieties you love most.
When Is the Best Time to Dig?
Timing is one of the most important factors when it comes to successfully overwintering your plants. You want to give the cannas as much time as possible to store energy, but you must get them out of the ground before the soil freezes solid.
Watch the Foliage
The best signal for digging comes from the plants themselves. In the fall, wait for the first "killing frost." This is a light freeze that turns the lush green or bronze leaves to a dark brown or black color. This frost tells the plant that it is time to go dormant.
Once the leaves have been hit by frost, the energy from the foliage begins to move down into the rhizome. This provides a final boost of nutrients that helps the plant survive its winter nap. If you live in an area where frost comes very late, you can simply wait until the leaves begin to yellow and die back naturally as the days get shorter.
Check the Calendar and Weather
In most northern regions, this usually happens in late September or October. It is perfectly fine to let the blackened foliage sit for a few days after the first frost. However, do not wait until the ground itself freezes. A hard freeze that penetrates several inches into the dirt can damage the rhizomes.
If a very early freeze is predicted and your cannas are still perfectly green, you can still dig them up. While the "frost signal" is helpful, it is not strictly required. The most important goal is to get the rhizomes into a protected space before the deep cold of winter sets in.
Key Takeaway Wait for the first light frost to turn the leaves brown before digging. This ensures the plant has stored maximum energy for the winter.
Identifying Your Garden Zone
Before you grab your shovel, it helps to know if digging is even necessary for your location. The USDA Plant Hardiness Zone Map is the best tool for this.
- Zones 8 and Warmer: In these southern regions, cannas are generally hardy. You can leave them in the ground year-round. A layer of mulch over the top is usually enough to keep them happy through the winter.
- Zone 7: This is the "middle ground" zone. In many years, cannas will survive in the ground here, especially if they are planted near a warm house wall. However, a particularly cold winter can still kill them. Many gardeners in Zone 7 choose to dig their favorite varieties just to be safe.
- Zones 6 and Colder: In these areas, the ground freezes deep enough to reach the rhizomes. Digging is required if you want to save your plants for next year.
We ship our bulbs and rhizomes based on these zones to ensure they arrive at the perfect planting time for your specific climate. Knowing your zone helps you plan your fall garden chores with confidence.
Essential Tools for Digging Cannas
You do not need a shed full of expensive equipment to dig cannas. A few basic hand tools will make the job quick and easy.
The Garden Fork
A sturdy garden fork (also called a spading fork) is the best tool for this job. Unlike a solid shovel blade, the tines of a fork can slide through the soil with less resistance. This reduces the chance of accidentally slicing through a large rhizome.
A Sharp Spade or Shovel
If you have very heavy or compacted soil, a sharp spade might be necessary to break the initial surface. Shovels are also useful for lifting the loosened soil away from the base of the plant.
Garden Pruners or a Small Saw
Canna stalks are thick and fibrous. You will need a good pair of bypass pruners or even a small serrated garden saw to cut the stalks back before you start digging.
Labels and Markers
If you grow several different varieties, it is very easy to get them mixed up once the leaves are gone. Have some waterproof labels and a permanent marker ready. Labeling your clumps immediately after digging saves a lot of guesswork in the spring.
Storage Containers
Think about where you will put the bulbs once they are out of the ground. Plastic bins, cardboard boxes, or even breathable mesh bags are all good options. You will also need some packing material like peat moss, vermiculite, or old newspapers to keep the rhizomes cushioned and slightly insulated.
Step-by-Step Guide: How to Dig Canna Bulbs
Now that you have your tools and the timing is right, it is time to head into the garden. Follow these steps to lift your cannas safely.
Step 1: Cut Back the Foliage
Start by removing the top growth. Use your pruners or saw to cut the stalks down to about 3 or 4 inches above the soil line. Leaving a short "handle" of stalk is helpful. It gives you something to hold onto while you shake off the dirt, and it makes the base of the plant easy to see.
Step 2: Loosen the Soil
Cannas grow outward as well as downward. The rhizome clump can be much wider than the original plant you put in the ground. To avoid damage, start digging at least 12 inches away from the center of the stalks.
Push your garden fork deep into the soil and gently rock it back and forth. Move in a circle around the entire plant, loosening the earth as you go. This breaks the tension of the roots and makes the final lift much easier.
Step 3: Lift the Clump
Once the soil is loose all the way around, slide your fork under the center of the clump. Using the handle for leverage, gently pry the entire mass upward. If you feel a lot of resistance, stop and loosen the soil a bit more. You want the clump to come up as one large piece if possible.
Step 4: Remove Excess Soil
Once the clump is out of the ground, lift it by the remaining stalks. Give it a gentle shake to remove the largest chunks of dirt. You can also use your hands to brush away loose soil. Do not worry about getting them perfectly clean yet. The goal is just to make them lighter and easier to handle.
Next Steps for Success
- Cut stalks to 4 inches above the soil.
- Start digging 1 foot away from the base.
- Circle the plant to loosen all sides.
- Lift the clump gently from underneath.
Preparing the Rhizomes for Storage
Lifting the plants is only the first half of the process. How you handle them immediately after digging determines how well they will survive the winter.
Cleaning and Inspection
Some gardeners prefer to wash their cannas with a garden hose to remove all the soil. This makes it very easy to see the health of the rhizome and any "eyes" for future growth. However, if your soil is sandy and falls away easily, washing might not be necessary.
If you do wash them, be very gentle. The skin of a freshly dug rhizome is soft and can bruise easily. Once they are clean, look for any soft spots, mold, or signs of insect damage. It is best to discard any pieces that look unhealthy now so they do not affect the rest of your collection.
To Divide or Not to Divide?
You have two choices: store the entire large clump or break it into smaller pieces now.
Storing the whole clump is often easier and takes less time in the fall. The outer rhizomes provide a bit of protection for the inner ones. However, large clumps take up more space.
Dividing now allows you to clean the pieces more thoroughly. Each division should have at least one or two "eyes" (the small, pointed bumps where new growth will start). If you divide them now, let the cut ends dry for a few extra days to form a "callus." This hard skin prevents rot-causing fungi from entering the plant.
The Curing Process
Curing is a fancy word for letting the rhizomes dry out slightly before you put them away. This is a vital step. If you put wet, freshly dug rhizomes into a sealed container, they will likely rot.
Place your cleaned cannas in a dry, frost-free area like a garage or a covered porch. Spread them out in a single layer on a piece of cardboard or a tarp. Let them air dry for 2 to 7 days. They are ready for storage when the outer skin feels dry and firm, and any remaining soil has turned to dust.
Best Methods for Winter Storage
The goal of storage is to keep the rhizomes dormant, cool, and just moist enough that they don't shrivel up completely.
Choose the Right Location
The ideal storage temperature is between 45°F and 55°F.
- Good spots: An unheated basement, a crawl space, or a cool closet.
- Avoid: Areas that freeze (like an uninsulated metal shed) or areas that stay too warm (like a laundry room or near a furnace).
Packing Materials
You want to surround the rhizomes with something that breathes but also holds a tiny bit of moisture.
- Peat Moss or Vermiculite: These are the gold standards. They are lightweight and help regulate moisture levels perfectly.
- Wood Shavings: Often sold as pet bedding, these work very well and are inexpensive.
- Newspaper: Wrapping individual rhizomes in several layers of newspaper is a great low-cost method.
- Plastic Bags with Holes: If using plastic bags, make sure to poke several large holes in the sides to allow for air circulation.
Packing the Containers
Place a layer of your chosen packing material in the bottom of a box or bin. Lay the rhizomes on top so they are not touching each other. Cover them with more material and repeat the process until the container is full. Do not snap a tight lid onto a plastic bin; leaving the lid slightly askew or using a cardboard box allows the plants to breathe.
Key Takeaway Successful storage requires a cool, dark location and a breathable packing material like peat moss or wood shavings.
Managing Container-Grown Cannas
Many of us grow medium cannas in large pots to decorate patios and decks. If you have container-grown plants, you have a few extra options for winter.
The "Dormant Pot" Method
If you have space in a cool basement or garage, you can store the entire pot. Once the foliage has been hit by frost, cut it back to the soil level. Stop watering the pot entirely. Move the container into your cool storage area. The dry soil in the pot acts as the "packing material" for the rhizomes. In the spring, you can simply bring the pot back out, give it fresh soil and water, and it will start growing again.
Digging from Pots
If your pots are too heavy to move or if you want to use the pots for winter evergreen displays, you should dig the cannas out. Follow the same steps as you would for in-ground plants. You will likely find that container cannas have very dense root systems, so you may need to use a sturdy trowel to pry the clump out of the pot.
Checking Your Cannas During the Winter
Storing cannas is not a "set it and forget it" task. We recommend checking on your stored rhizomes once a month. This small effort ensures that you don't lose your plants to unexpected issues.
Looking for Dryness
If the rhizomes feel very light or look shriveled, they are getting too dry. Use a spray bottle to lightly mist the packing material with water. You don't want it to be wet, just slightly damp to the touch. This provides enough humidity to keep the rhizomes plump and healthy.
Identifying Rot
If you find any soft, mushy, or foul-smelling spots, that rhizome is starting to rot. Remove it immediately and throw it away. Rot can spread quickly from one piece to another, so removing the "bad apple" protects the rest of your collection. If the packing material feels soggy, replace it with fresh, dry material.
Planning for Spring Replanting
While the winter may seem long, the time to replant will be here before you know it. Knowing how your cannas are doing in storage helps you plan your spring garden layout.
As the weather warms up in late March or April, you can start checking for signs of life. You might see small white or pink "eyes" beginning to swell on the rhizomes. This is an exciting sign that the plants are ready to grow!
If you want to get a head start, you can plant your rhizomes in pots indoors about 4 to 6 weeks before the last frost date. Place them in a sunny window and keep the soil lightly moist. By the time the outdoor temperatures are consistently warm, you will have established plants ready to go into the ground. This often results in earlier blooms and a longer season of color.
Simple Tips for Success
At Longfield Gardens, we believe that gardening should be a joy, not a chore. Here are a few final tips to make your canna digging experience as easy as possible:
- Work on a Dry Day: Digging is much easier (and cleaner) when the soil isn't muddy. If rain is in the forecast, try to dig a day or two before the storm.
- Use Your Body, Not Just Your Back: When prying up large clumps, bend your knees and use the garden fork as a lever. Let the tool do the heavy lifting for you.
- Label as You Go: Even if you think you will remember which one is the Red Velvet and which is the "Yellow King Humbert," labels are your best friend.
- Involve the Family: Digging cannas is a great activity for kids or grandkids. It feels like a treasure hunt as you pull the hidden rhizomes out of the dirt.
Conclusion
Digging and storing canna bulbs is a wonderful way to connect with the cycle of the seasons. It transforms a one-summer plant into a lifelong garden companion. By following these simple steps, you can protect your investment and enjoy a lush, tropical landscape year after year.
We take great pride in providing high-quality plants and back them with our 100% Quality Guarantee. Taking the time to care for your cannas over the winter is a testament to the love and effort you put into your garden. When those first sprouts emerge next spring, you will feel a great sense of satisfaction knowing you helped them through the winter.
- Wait for the first frost to signal dormancy.
- Use a garden fork to lift clumps gently.
- Cure the rhizomes for a few days before packing.
- Store in a cool, dark place in breathable material.
Saving your cannas is a rewarding fall ritual that ensures your garden will be filled with vibrant color and stunning foliage for many seasons to come.
Ready to add more beauty to your garden? Browse our canna collection and find the perfect varieties to complement your growing collection.
FAQ
Can I leave my cannas in the ground if I use a lot of mulch?
This depends on your USDA hardiness zone. In Zone 7, a thick 6-to-8-inch layer of straw or wood chips can often protect cannas through the winter. However, in Zone 6 and colder, even heavy mulching is usually not enough to prevent the ground from freezing deep enough to damage the rhizomes.
Do I have to wait for a frost before digging them up?
While a light frost is a great natural signal for the plant to go dormant, it is not strictly necessary. If your schedule is busy or the weather is turning very cold early, you can dig them while the leaves are still green. Just be sure to cut the stalks back and follow the curing process to ensure they are ready for storage.
What is the best material to store canna rhizomes in?
The most popular and effective materials are peat moss, wood shavings (like those used for pet bedding), or vermiculite. These materials are excellent because they allow for air circulation while holding onto just enough moisture to keep the rhizomes from drying out completely. You can also use shredded paper or wrap them in several layers of old newspaper.
Why did my stored canna bulbs rot last year?
Rot is usually caused by too much moisture or poor air circulation during storage. This can happen if the rhizomes weren't cured (dried) enough before being packed away, or if they were stored in a completely sealed plastic container. To prevent this, ensure they are dry to the touch before storing and check them monthly to remove any soft pieces.