What to Do With Canna Lily Bulbs: A Seasonal Guide

Table of Contents

1. Introduction
2. Understanding Your Canna Lily "Bulbs"
3. When to Take Action in the Fall
4. Step-by-Step: Digging Up the Rhizomes
5. The Importance of Curing
6. Choosing Your Storage Method
7. Monitoring During the Winter
8. Dividing for More Plants
9. Getting a Head Start in the Spring
10. Moving to the Garden
11. Routine Care for Maximum Beauty
12. Troubleshooting Common Issues
13. The Longfield Gardens Quality Promise
14. Conclusion
15. FAQ

Introduction

There is nothing quite like the sight of a canna lily in full bloom during the height of summer. These tropical wonders bring a sense of exotic luxury to any backyard with their oversized, banana-like leaves and brilliant, nectar-rich flowers. Whether you love the way they attract hummingbirds or the bold architectural statement they make in a garden bed, cannas are a highlight of the growing season. Many gardeners look forward to the "canna season" as the time when the landscape truly feels lush and vibrant.

At Longfield Gardens, we want to help you enjoy these spectacular cannas year after year. While they look like they belong in a rainforest, they are actually quite easy to manage throughout the changing seasons. The key to their longevity lies in understanding how to handle their underground energy stores once the weather turns cold. Because they are tropical by nature, they need a little bit of assistance to survive the winter months in most parts of the United States.

This guide will walk you through exactly what to do with canna lily bulbs from the moment the first frost hits until it is time to plant them again in the spring. We will cover the best practices for digging, curing, storing, and dividing your plants so you can expand your collection every year. Knowing what to do with canna lily bulbs ensures that your garden remains a tropical paradise for many summers to come. For a broader overview, see All About Cannas.

Understanding Your Canna Lily "Bulbs"

Before we jump into the seasonal chores, it is helpful to understand what we are actually working with. While most gardeners use the term "bulbs," canna lilies actually grow from rhizomes. A rhizome is a thick, fleshy underground stem that grows horizontally just beneath the soil surface. This structure acts as a storage tank, holding all the energy and nutrients the plant needs to send up those massive stalks and flowers.

In warm climates—specifically USDA hardiness zones 9 and 10, which you can check on the USDA hardiness zone map—cannas can stay in the ground all year. In these regions, they act like any other perennial, resting during the winter and waking up when the soil warms. However, for gardeners in zones 8 and colder, the freezing winter temperatures will turn these fleshy rhizomes into mush if they are left in the soil. This is why digging and storing them is such an important part of the gardening calendar.

Think of the rhizome as a gift that keeps on giving. Over a single summer, one small piece can grow into a large, multi-segmented clump. This natural multiplication is one of the most rewarding aspects of growing cannas. When you learn how to handle these rhizomes properly, you will find that your original investment in a few plants can eventually fill your entire yard with color.

When to Take Action in the Fall

Timing is everything when it comes to preparing cannas for their winter nap. You want to give the plants as much time as possible to store energy in their rhizomes, but you must beat the arrival of a deep, ground-penetrating freeze. The signal to start the process is usually provided by nature itself in the form of the first light frost.

When the temperatures dip just below freezing at night, you will notice the lush green or burgundy foliage of your cannas turns dark brown or black almost overnight. The leaves will look wilted and limp. While this might look disappointing, it is actually the perfect indicator that the plant has finished its work for the year. The cold has told the plant to move its energy down into the rhizome.

Wait for this first frost before you begin digging. A light surface frost will kill the foliage but will not harm the rhizome protected under the soil. However, you should not wait until the ground itself freezes solid. A hard freeze that reaches several inches into the dirt can damage the moisture-rich rhizomes and cause them to rot later in storage. Aim to have your cannas out of the ground within a week or two of that first blackened foliage appearing. For more timing help, see When Do I Dig Up Canna Lily Bulbs?.

Key Takeaway: The best time to dig up your cannas is shortly after the first light frost has turned the leaves brown, but before the ground freezes hard.

Step-by-Step: Digging Up the Rhizomes

Digging up canna rhizomes is a satisfying autumn task that allows you to see exactly how much your plants have grown. You do not need specialized equipment—a standard garden spade or a sturdy garden fork will do the job perfectly. The goal is to lift the entire root mass without slicing through the fleshy rhizomes.

Start by cutting the stalks down. Use a pair of clean garden shears or a sharp knife to cut the stems about 2 to 4 inches above the soil line. Removing the bulky foliage first makes it much easier to see where you are digging and helps you handle the roots more effectively. You can compost the healthy green stems, but if you noticed any pest issues during the summer, it is better to discard the foliage in the trash.

Next, give the plant some space. Canna rhizomes can spread surprisingly far in a single season. Place your spade or fork about 8 to 12 inches away from the base of the stems. Dig straight down and gently pry upward to loosen the soil. Work your way around the entire clump until you can lift the whole mass out of the ground. If the clump is very large and heavy, you can use your shovel to carefully split it into two manageable halves while it is still in the hole.

Cleaning and Initial Inspection

Once the rhizomes are out of the ground, shake off as much loose soil as possible. You can use your hands to gently brush away dirt or give the clump a light tap against the side of a garden crate. Some gardeners prefer to use a garden hose to wash the rhizomes clean, which is fine as long as you allow them to dry thoroughly afterward.

As you clean the rhizomes, keep an eye out for any that feel soft, mushy, or look obviously diseased. A healthy canna rhizome should feel firm, much like a fresh potato. If you find any damaged sections, you can simply snap or cut them off and discard them. This prevents any potential rot from spreading to the healthy parts of the clump during the winter.

The Importance of Curing

One of the most common mistakes in canna care is putting the rhizomes directly into storage while they are still wet or freshly dug. This often leads to mold or rot. To prevent this, you must "cure" the rhizomes. Curing is simply the process of letting the outer skin of the rhizome dry and toughen up slightly before it goes into a box for the winter.

Find a dry, sheltered spot for this process. A garage, a garden shed, or even a covered porch works well. Spread the rhizomes out in a single layer on a tarp, a piece of cardboard, or in a shallow tray. They should not be piled on top of each other, as they need good airflow to dry properly.

Let the rhizomes sit for about 7 to 10 days. During this time, the remaining soil will dry into a fine dust that is easy to brush off, and any small nicks or cuts from the digging process will "callous" over. This callous acts as a protective barrier against fungi. After a week of curing, your cannas will be much better prepared to stay healthy and dormant until spring.

What to do next:

• Cut stalks to 3 inches above the soil.
• Lift the root mass with a garden fork.
• Brush off loose soil and inspect for firmness.
• Air-dry (cure) in a cool, dry place for one week.

Choosing Your Storage Method

There are several ways to store canna lily bulbs, and the best one for you often depends on the space you have available. The goal for all methods is the same: keep the rhizomes cool (but not freezing), dark, and slightly insulated so they do not dry out completely. Ideally, you want to maintain a temperature between 40°F and 50°F.

The Box and Peat Moss Method

This is a very reliable method that helps regulate moisture perfectly. Line a cardboard box or a plastic crate with a few layers of newspaper. Place a layer of slightly damp (but not wet) peat moss, vermiculite, or perlite in the bottom. Arrange your cured rhizomes on top so they are not touching each other, then cover them with more of the medium. You can stack a second layer if needed. The peat moss absorbs excess moisture but provides enough insulation to keep the rhizomes from shriveling.

The Paper Bag Method

If you only have a few cannas, paper grocery bags are an easy and breathable option. Place the rhizomes in the bag and fill the gaps with shredded newspaper or wood shavings. Fold the top of the bag loosely. This allows for air exchange while keeping the light out. Avoid using sealed plastic bags, as these trap moisture and almost always lead to rot.

Storing in Containers

If you grew your cannas in pots over the summer, our Summer Blooming Bulbs for Containers collection is an even easier option. Once the foliage has died back and you have cut the stalks down, you can simply move the entire pot—soil and all—into a cool basement or garage. The dry soil in the pot acts as a natural insulator. You won't need to water the pot at all during the winter; just let the rhizomes sleep in the dark until spring arrives.

Monitoring During the Winter

While it is tempting to "set it and forget it," your cannas will benefit from a quick check-up once a month during the winter. This takes only a few minutes but can save your entire collection if conditions aren't quite right.

When you check your rhizomes, you are looking for two things: rot and desiccation (extreme drying out). If a rhizome feels mushy or has visible mold, remove it immediately so it doesn't infect its neighbors. If the rhizomes look very shriveled and feel lightweight, they may be getting too dry. In this case, use a spray bottle to lightly mist the storage medium (the peat moss or wood shavings) with water. Do not soak the rhizomes; just add enough moisture to the air inside the box to stop the shriveling.

If you find that your storage area is getting too warm (above 55°F), the cannas might try to start growing prematurely. You will see small white or pale green sprouts beginning to push out. If this happens, try to find a slightly cooler spot for them. They should remain dormant until you are ready for them to wake up in the spring.

Dividing for More Plants

One of the most exciting parts of knowing what to do with canna lily bulbs is the chance to divide them. Because cannas grow so vigorously, you will likely have many more plants in the spring than you had in the fall. Dividing is a simple way to expand your garden or share plants with friends and neighbors.

You can divide your cannas either in the fall after curing or in the spring before planting. Many gardeners prefer spring division because it is easier to see the "eyes" or growth points once the plant begins to wake up.

To divide a clump, look for the individual segments of the rhizome. Each piece you save must have at least one (and preferably two or three) "eyes." These eyes look like small, rounded bumps or points, similar to the eyes on a potato. Use a clean, sharp knife to cut the rhizomes into sections. Each section should be firm and several inches long. If you divide them in the fall, let the cut ends dry for a day before putting them into storage. If you divide in the spring, you can plant the pieces directly into pots or the ground.

Getting a Head Start in the Spring

Cannas love heat. In many northern states, the soil doesn't warm up enough for cannas to start growing until late May or even June. If you wait until then to plant, you might not see flowers until late in the summer. To enjoy a longer bloom season, we recommend giving your canna bulbs a "head start" indoors.

About 4 to 6 weeks before the last expected frost in your area, bring your storage boxes out of the cold. Inspect the rhizomes one last time and discard any that didn't make it through the winter. Pot the healthy rhizomes into individual nursery pots using a standard potting mix. For a step-by-step refresher, see How to Plant Canna Lily Bulbs.

Place the pots in a warm, sunny window or under grow lights. You only need to water them sparingly at first—just enough to keep the soil from being bone-dry. Once you see the first green spikes emerging from the soil, you can increase the watering. By the time the weather is warm enough to plant outside, you will have healthy, established plants that are already 6 to 12 inches tall. This can result in flowers up to a month earlier than if you had planted the dry rhizomes directly in the garden.

Moving to the Garden

The final step in the process is returning your cannas to their summer home. Because they are tropical, they have no tolerance for frost. Wait until all danger of frost has passed and the soil has warmed to at least 60°F or 65°F. If the soil is too cold and wet, the rhizomes will simply sit there and may even rot before they have a chance to grow.

Site Selection

Choose a spot that receives full sun—at least 6 to 8 hours of direct light per day. While cannas will grow in partial shade, they will not flower as well, and their foliage colors won't be as vivid. They are also "heavy feeders," meaning they appreciate soil that is rich in organic matter. Mixing some compost or well-rotted manure into the planting area will give them the fuel they need for their rapid growth.

Planting Depth and Spacing

If you are planting dormant rhizomes directly into the ground, plant them about 2 to 3 inches deep. Place the rhizome horizontally in the hole with the eyes facing up. If you cannot tell which way is up, don't worry—the plant will figure it out and grow toward the light. Taller cannas need more room for air circulation, while dwarf varieties can be planted a bit closer together.

For cannas that you started early in pots, plant them at the same depth they were growing in the pot. Be sure to "harden them off" by placing the pots outside in a sheltered spot for a few hours a day for a week before planting. This helps the tender indoor leaves adjust to the wind and stronger sun of the outdoors.

Key Takeaway: Success with cannas comes down to heat and moisture. Wait for warm soil, provide plenty of sun, and keep them well-watered throughout the summer.

Routine Care for Maximum Beauty

Once your cannas are back in the ground, they are relatively low-maintenance, but a few simple tasks will keep them looking their best. Cannas are thirsty plants. Because they have such large leaves, they lose a lot of moisture through evaporation. During the heat of the summer, they may need a deep watering two or three times a week if it doesn't rain. Mulching around the base of the plants with bark or straw is a great way to help the soil stay moist.

Fertilizing is also beneficial. A balanced, all-purpose fertilizer applied once a month during the growing season will encourage more flowers and larger leaves. If you are growing cannas in containers, they may need fertilizer every two weeks, as nutrients wash out of pots more quickly.

Don't forget to deadhead. As the flowers fade, snip off the spent blooms. This prevents the plant from putting energy into seed production and encourages it to send up more flower spikes. Just be careful not to cut off the secondary buds that often form right next to the main flower cluster.

Troubleshooting Common Issues

While cannas are generally robust, you might occasionally run into a few hurdles. Leading with the right care usually prevents these issues before they start.

If your cannas aren't blooming, the most common reason is a lack of sunlight. Moving them to a sunnier spot next year is the easiest fix. Another reason can be a lack of nutrients; a quick boost of fertilizer often helps.

If you see holes in the leaves or "rolled" leaves that don't unfurl properly, you might have canna leaf rollers. These are small caterpillars that hide inside the leaves. The best approach is to keep a close eye on your plants in early summer. If you see signs of damage, you can manually remove the affected leaves or consult your local extension office for safe treatment options in your area.

Finally, if your plants look stunted or yellowed despite having plenty of water and sun, check the soil drainage. While cannas like moisture, they do not like to sit in stagnant, waterlogged soil for long periods. If your soil is heavy clay, planting them in raised beds or large containers can provide the better drainage they need to thrive.

The Longfield Gardens Quality Promise

We believe that every gardener should have the opportunity to experience the joy of tropical blooms. At Longfield Gardens, we work closely with experienced growers to ensure you receive the highest quality canna rhizomes. Our rhizomes are graded to ensure they have multiple healthy eyes, giving you a head start on a successful growing season.

We stand behind our plants with a 100% quality guarantee. We make sure our items are true to variety and arrive at your door in prime condition. If you ever have a concern about the quality of your delivery, our team is ready to help you right away. Our goal is to make gardening a rewarding and successful part of your life.

Whether you are a seasoned expert or planting your very first "bulb," we are here to support you with practical advice and premium plants. We want to see your garden flourish as much as you do.

Conclusion

Understanding what to do with canna lily bulbs is one of the most useful skills a home gardener can develop. By following a simple cycle of digging, curing, and storing, you can turn a single season of tropical beauty into a lifetime of garden highlights. For even more warm-weather options, browse our Spring-Planted Summer-Blooming Bulbs.

• Wait for the frost: Let the first cold snap signal the end of the season.
• Dry before you store: Always cure your rhizomes to prevent rot.
• Keep it cool: Find a dark, frost-free spot for winter storage.
• Start early: Pot them up indoors in the spring for more flowers. If you want to plan by palette, browse Shop by Color - Spring-Planted Bulbs.

Gardening is a journey of discovery, and cannas are some of the most exciting companions you can have along the way. We encourage you to try different varieties and see how they can transform your landscape. For larger plantings, check out our Spring-Planted Flower Bulk Buys.

"The secret to beautiful cannas isn't complex chemistry; it's simply respecting their tropical roots and giving them a safe place to rest during the winter."

FAQ

Can I leave my canna lilies in the ground over winter?

This depends entirely on your location. If you live in USDA zones 9 or 10, cannas can typically stay in the ground year-round with just a layer of mulch for protection. If you are in zone 8 or colder, the rhizomes will likely freeze and rot, so it is best to dig them up and store them indoors.

Do I need to wash the dirt off the bulbs before storing?

It is not strictly necessary to wash them, and sometimes it is better not to. Shaking or brushing off the loose soil is usually enough. If you do wash them with a hose to see the "eyes" more clearly, you must ensure they are 100% dry before putting them into a box, or they will grow mold.

My stored canna bulbs look shriveled; are they dead?

Not necessarily! Canna rhizomes often look a bit shriveled or "sad" by late winter. As long as they still feel firm when you squeeze them, they are likely just fine. If they feel light as air and crumble when squeezed, they have dried out too much, but if they are firm, they will plump back up once they are planted and watered.

When is the best time to divide my canna clumps?

The most popular time to divide cannas is in the spring, just as you are getting ready to plant them. It is easier to see the growing points (eyes) at this time, which helps you make better cuts. However, you can also divide them in the fall if you have limited storage space and need to fit them into smaller boxes.