Can Canna Bulbs Be Left in the Ground?

Table of Contents

1. Introduction
2. Understanding the Growth Habit of Cannas
3. Check Your USDA Hardiness Zone
4. Leaving Cannas in the Ground: Success Strategies
5. When You Must Lift Your Cannas
6. Curing and Cleaning Your Rhizomes
7. Storing Your Cannas for Winter
8. Dividing Cannas for More Plants
9. Waking Up Cannas in the Spring
10. Common Myths About Canna Care
11. Choosing the Right Variety for Your Space
12. Summary of Winter Care by Zone
13. Conclusion
14. FAQ

Introduction

Canna lilies are the ultimate summer showstoppers. With their towering heights, lush tropical foliage, and vibrant blooms, they bring a sense of vacation-style relaxation to any backyard. Whether you are growing classic varieties like The President or the striking striped leaves of ‘Pretoria’, these plants are surprisingly easy to care for during the heat of July and August.

At Longfield Gardens, we want to help you enjoy these tropical beauties year after year. The answer to whether you can leave your cannas in the garden through the winter depends mostly on your local climate and your soil conditions, especially for striped favorites like Pretoria. For some gardeners, these plants are reliable perennials that return on their own. For others, a little extra winter care is the key to preserving those prized rhizomes for the following spring.

This guide will help you determine the best winter strategy for your specific area. We will cover how to identify your hardiness zone, how to protect cannas that stay in the ground, and the simple steps for storing them if your winters are a bit too cold. By understanding a few basic rules, you can ensure your garden stays filled with tropical color every single summer. If you want to browse the tallest selections first, start with our Tall Cannas.

Whether you are a seasoned pro or a beginner, keeping your cannas healthy through the winter is a rewarding part of the gardening cycle. With the right preparation, you can look forward to even bigger and better blooms next season.

Understanding the Growth Habit of Cannas

To understand how cannas handle the winter, it helps to know how they grow. Although most of us call them "bulbs," cannas actually grow from thick, fleshy underground stems called rhizomes. These rhizomes act as energy storage units for the plant. During the sunny summer months, the large leaves soak up sunlight and convert it into energy, which is then stored in the rhizome to fuel the next year’s growth. For a fuller overview of canna basics, see All About Cannas.

Because cannas are native to tropical and subtropical regions of the Americas, they are designed for warm weather. They do not have a natural internal mechanism to survive deep, frozen ground. In their native habitats, they might experience a dry season where they go dormant, but they never have to deal with the expansion and contraction of frozen soil.

The goal of winter care is simply to keep that fleshy rhizome from freezing or rotting. If the rhizome stays firm and healthy, the plant will wake up as soon as the soil warms up in the spring. If the rhizome freezes solid, the cells inside rupture, and the plant will not be able to grow.

Key Takeaway: Cannas store all their future growth energy in their underground rhizomes. Keeping these rhizomes safe from freezing temperatures is the most important part of winter care.

Check Your USDA Hardiness Zone

The most significant factor in deciding whether to leave your canna bulbs in the ground is your USDA hardiness zone. These zones are based on the average minimum winter temperature in your area. You can easily find your zone by using a zip code look-up tool on our website or the USDA’s official map. See our Hardiness Zone Map to check your growing zone.

Zones 8 to 11: The "Safe" Zones

If you live in Zone 8, 9, 10, or 11, you are in luck. In these warmer climates, the ground rarely freezes deep enough to reach the canna rhizomes. Most gardeners in these areas can leave their cannas in the ground all year round. The plants will naturally die back to the ground after the first light frost and enter a period of dormancy. In the spring, they will sprout again from the same spot.

Zone 7: The Transition Zone

Zone 7 is where things get interesting. In this region, cannas can often survive the winter in the ground, but it isn't always a guarantee. A particularly wet or unusually cold winter could pose a risk. Many gardeners in Zone 7 choose to leave their cannas in place but provide a thick layer of protection to act as an outdoor blanket.

Zones 3 to 6: The "Lift and Store" Zones

In these cooler climates, the ground freezes several inches (or even feet) deep. If canna rhizomes are left in the ground here, they will likely freeze and turn to mush. For gardeners in these zones, the best approach is to "lift" the rhizomes in the autumn and store them in a frost-free place until spring. While this takes a little extra effort, it is a very straightforward process that ensures your favorite varieties return year after year.

Leaving Cannas in the Ground: Success Strategies

If you live in a climate where cannas can stay in the ground, there are still a few things you can do to set them up for success. Just because the air temperature stays relatively mild doesn't mean the soil doesn't need a little attention.

Wait for the First Frost

Even if you plan to leave your cannas in the ground, do not rush to cut them back in late summer. Let the foliage stay on the plant as long as possible. The longer the leaves are green, the more energy they are sending down to the rhizomes for next year. Once a light frost hits, the leaves will turn brown or black. This is your signal that the plant has entered dormancy.

Cutting Back the Foliage

Once the leaves have browned, use a pair of clean garden shears to cut the stems down to about 2 to 4 inches above the soil line. Removing the old, dead foliage helps prevent pests or diseases from overwintering in the garden debris. It also makes the garden look much tidier during the winter months.

The Importance of Drainage

The biggest threat to cannas in the ground during winter isn't always the cold—it is often the moisture. If cannas sit in cold, soggy soil for months, the rhizomes can rot. If your garden has heavy clay soil that stays wet, you might consider lifting your cannas even if you live in a warmer zone. If your soil drains well, your cannas are much more likely to survive and thrive.

Mulching for Extra Protection

For gardeners in Zone 7 and even Zone 8, a thick layer of mulch is the best insurance policy. Mulch acts as an insulator, keeping the soil temperature more consistent and preventing the frost from penetrating deep into the earth.

• Materials to Use: Clean straw, shredded bark, pine needles, or chopped leaves all work well.
• Depth: Apply a layer at least 4 to 6 inches thick over the top of the planting area.
• Coverage: Make sure the mulch extends a few inches beyond the actual stems to protect the entire root zone.

What to do next:

1. Wait for the first frost to turn the leaves brown.
2. Cut stems down to 3 inches above the soil.
3. Clean up any fallen leaf debris.
4. Apply a thick 6-inch layer of straw or bark mulch.
5. Mark the spot so you don't accidentally dig them up in early spring.

When You Must Lift Your Cannas

If you live in Zone 6 or colder, lifting your cannas is the best way to ensure they survive. For a step-by-step guide, see Storing Canna Lily Bulbs: A Simple Winter Care Guide. While it might sound like a big chore, it is actually a very peaceful autumn activity that allows you to get a close look at the health of your plants.

Timing the Harvest

Timing is everything when it comes to lifting cannas. You want to wait until the first frost has blackened the foliage. This frost tells the plant to move all its remaining resources into the rhizome. However, you don't want to wait so long that the ground begins to freeze solid. Usually, a week or two after the first frost is the perfect window.

How to Lift Canna Rhizomes

To lift the rhizomes without damaging them, follow these simple steps:

1. Cut back the stems: Cut the stalks down to about 4 inches. This gives you a "handle" to hold onto while you work.
2. Loosen the soil: Use a garden fork or a spade. Start digging about 6 to 10 inches away from the base of the plant. Cannas can spread quite a bit underground, and you want to avoid slicing into the fleshy rhizomes.
3. Lift gently: Gently pry the entire clump out of the ground. It is often easier to lift the whole mass rather than trying to separate individual pieces while they are still in the soil.
4. Shake off excess dirt: You don't need to scrub them clean or wash them with a hose. In fact, keeping them dry is better. Just gently knock off the large clumps of soil.

Curing and Cleaning Your Rhizomes

Before you put your cannas away for their winter nap, they need a short period of "curing." Curing allows the outer skin of the rhizome to toughen up slightly, which helps prevent rot and dehydration during storage. For more detailed winter care, see How to Care for Canna Lily Bulbs.

The Curing Process

Move your lifted clumps to a dry, frost-free area like a garage, shed, or porch. Spread them out on a layer of newspaper or cardboard. Let them sit for a few days (usually 2 to 7 days, depending on the humidity). You want the remaining soil to feel dry to the touch and the cut ends of the stems to look calloused.

Final Cleaning

Once the rhizomes are dry, you can gently brush off any remaining loose soil. At this stage, you should also inspect the rhizomes. If you see any soft, mushy spots or areas that look like they are rotting, cut those parts away with a clean knife. Only store firm, healthy-looking rhizomes. You can also trim off any long, stringy roots that are hanging off the bottom of the rhizomes.

Key Takeaway: A short drying period (curing) is the secret to successful storage. It prevents moisture from being trapped against the rhizome, which is the primary cause of winter rot.

Storing Your Cannas for Winter

The goal of storage is to keep the rhizomes in a "Goldilocks" state: not so cold that they freeze, and not so warm that they start growing prematurely. The ideal temperature for storage is between 40°F and 50°F.

Choosing a Storage Container

There are several ways to store canna rhizomes, and the best one for you depends on what you have on hand:

• Cardboard Boxes: This is a classic method. Line the box with newspaper and place the rhizomes inside.
• Paper Bags: Large grocery bags work well for smaller quantities.
• Plastic Totes: If you use plastic, do not seal the lid completely. The rhizomes are living things and need a small amount of air circulation to prevent mold.

Storage Mediums

Many gardeners find that "packing" the rhizomes in a dry material helps regulate moisture. You can use:

• Peat Moss: This is the most popular choice as it holds a tiny bit of moisture without being wet.
• Vermiculite or Perlite: These are great for keeping things airy and dry.
• Wood Shavings: Often sold as pet bedding, these are inexpensive and effective.
• Dry Sand: A traditional method that works well in very dry basements.

Simply place a layer of your chosen medium in the bottom of the container, add a layer of rhizomes (making sure they aren't touching each other), and cover them with more medium.

Where to Keep Them

An unheated basement, a crawl space, or a cool closet in a mudroom are usually the best spots. Avoid keeping them in an attached garage if the temperature there drops below freezing. Check on your rhizomes once a month. If they look shriveled, lightly mist the storage medium with a tiny bit of water. If any look soft or moldy, remove them immediately to protect the rest of the batch.

Dividing Cannas for More Plants

One of the most exciting things about cannas is how much they grow in a single season. A single rhizome planted in May can turn into a massive clump by October. When you lift your cannas in the fall (or before you plant them in the spring), it is the perfect time to divide them. For an easy mix of colors, browse our Assorted Cannas.

Dividing is simple. Look for the "eyes" on the rhizome—these are the small bumps or points where new stems will grow. You can use a sharp, clean knife to cut the large clump into smaller pieces. Just make sure each piece has at least one or two healthy eyes and a good amount of the fleshy rhizome attached.

This is a wonderful way to expand your garden for free or to share your favorite varieties with friends and neighbors. We love seeing how a single purchase from us can eventually fill an entire garden border over a few seasons.

Waking Up Cannas in the Spring

Whether you left your cannas in the ground or stored them in the basement, spring is the time to get them moving again.

For Cannas Left in the Ground

In the spring, wait until the danger of frost has passed and the soil has begun to warm up. Peel back the layer of mulch you applied in the fall. You will likely see small, pointed "spears" of new growth poking through the soil. Once you see this growth, you can apply a balanced slow-release fertilizer to give them a boost for the coming season. For planting depth details, see How Deep Do You Plant Canna Bulbs?.

For Stored Cannas

If you stored your rhizomes, you have two options:

1. Direct Planting: Wait until the soil temperature is at least 60°F. Plant the rhizomes about 4 to 6 inches deep and 1 to 2 feet apart, depending on the variety.
2. Early Start: If you want flowers sooner, you can "pot up" your cannas indoors about 4 to 6 weeks before the last frost date. Place the rhizomes in pots with potting soil, keep them in a warm, sunny spot, and water them lightly. By the time the weather is warm enough to move them outside, you will already have established plants.

What to do next:

1. Check your local frost dates.
2. Inspect stored rhizomes for firm texture and healthy eyes.
3. Prepare the garden bed by adding a little compost.
4. Plant with the "eyes" facing upward.
5. Water once at planting, then wait for sprouts before watering regularly.

Common Myths About Canna Care

There is a lot of advice online about cannas, and some of it can be a bit confusing. Let’s clear up a few common misconceptions:

Myth: You have to wash them with bleach before storing. While some people recommend a fungicide dip, it is usually unnecessary for home gardeners. As long as you cure them properly and keep them in a cool, dry place, they will stay healthy on their own.

Myth: Cannas are "bulbs" and should be planted deep like tulips. Cannas are rhizomes and prefer to be planted relatively shallow. Planting them 4 to 6 inches deep is perfect. If you plant them a foot deep, they will struggle to send shoots to the surface, and you will wait much longer for flowers.

Myth: You can't grow them in pots. Cannas actually thrive in large containers! If you want compact choices, browse Short Cannas. This is a great option for gardeners in cold zones because you can simply move the entire pot into a frost-free garage for the winter without ever having to dig up the rhizomes.

Choosing the Right Variety for Your Space

When you are planning your garden, consider the mature size of the canna. Some varieties, like 'Musifolia', are grown primarily for their massive, banana-like leaves and can reach 8 to 10 feet tall. If you want to compare size categories, see How Tall Do Canna Bulbs Grow?.

Other varieties are more compact. 'Lucifer' or City of Portland usually stay around 3 to 4 feet tall, making them ideal for the middle of a flower bed or for large patio containers. At Longfield Gardens, we offer a range of heights and colors so you can find the perfect fit for your landscape.

Matching the right plant to the right place is the first step toward a successful garden. Cannas love full sun—at least 6 to 8 hours a day—and they appreciate consistent moisture during the peak of summer. If you give them these two things, they will reward you with lush growth regardless of which winter strategy you choose.

Summary of Winter Care by Zone

To make it easy, here is a quick reference for what to do with your cannas this winter:

• Zones 8-11: Leave them in the ground. Cut back dead foliage after frost and enjoy the low-maintenance perennial lifestyle.
• Zone 7: Leave them in the ground but apply a 6-inch layer of mulch for safety. If your soil is very wet, consider lifting them.
• Zones 3-6: Lift the rhizomes after the first frost. Cure them for a few days, then store them in a cool, dry place in a medium like peat moss or wood shavings.

Conclusion

Gardening is all about working with nature and learning what your specific patch of earth needs to thrive. Whether you live in a warm climate where cannas are a permanent fixture or in a cooler region where lifting them is a seasonal tradition, the effort is well worth the reward. The spectacular tropical foliage and bold flowers of cannas are unmatched in the summer garden.

At Longfield Gardens, we take pride in providing high-quality rhizomes that are ready to burst into growth as soon as the weather warms up. By following these simple winter care steps, you can protect your investment and enjoy a more beautiful yard year after year. Remember, there is no single "perfect" way to garden—just the way that works best for you and your plants.

"The cycle of the seasons is part of the joy of gardening. Protecting your plants in the winter makes the first sprouts of spring feel like a true celebration."

We are here to support you every step of the way. If you have questions about your specific climate or need help choosing the best varieties for your garden, don't hesitate to Contact Us. Happy gardening!

FAQ

What happens if I leave my cannas in the ground in Zone 6?

In Zone 6, the ground usually freezes deep enough to reach the canna rhizomes. If the rhizomes freeze, they will turn to mush and will not grow back in the spring. To ensure your cannas survive in Zone 6, it is best to lift them in the fall and store them in a frost-free area like a basement or cool closet.

How do I know if my stored canna rhizomes are still good?

A healthy canna rhizome should feel firm to the touch, much like a fresh ginger root or a potato. If the rhizome feels light, hollow, or shriveled, it may have dried out too much. If it feels soft, squishy, or has a foul smell, it has likely rotted and should be discarded to prevent it from affecting other healthy rhizomes.

Do I need to water my cannas while they are in storage?

Generally, no. Canna rhizomes should be kept dry to prevent rot. However, if you check them mid-winter and they look extremely shriveled or dry, you can lightly mist the packing material (like peat moss) with a spray bottle. You want the material to be barely damp, never wet.

Can I leave cannas in pots over the winter?

Yes, if you live in a cold climate, you can leave the cannas in their pots. Once the frost hits, cut the foliage back and move the entire pot into a frost-free garage or basement. For more potting ideas, see How to Grow Summer Bulbs in Containers. Do not water them during the winter. In the spring, you can move the pot back outside, give it a good watering, and the plants will begin to grow again.