Introduction
Imagine stepping into your backyard and feeling like you have been transported to a tropical island. The sun is warm, the air is still, and your garden is filled with towering plants boasting massive, paddle-shaped leaves and vibrant, orchid-like flowers. This is the magic of the canna lily. At Longfield Gardens, we believe every gardener should experience the joy of growing these architectural wonders. They are some of the most rewarding plants you can add to a summer landscape.
If you are new to these plants, you might find yourself asking exactly what are canna bulbs and how they differ from the tulips or daffodils you plant in the fall. While they are often sold and discussed as "bulbs," there is a bit more to their story. Understanding their unique structure and growth habits is the first step toward a successful growing season. You can also browse our selection of tall cannas for dramatic summer color.
This guide will explain what these plants are, how they grow, and why they have become a staple in American gardens. Whether you have a sprawling backyard or a small sunny balcony, these plants offer a simple way to add dramatic height and vivid color. Canna bulbs are versatile, heat-loving rhizomes that provide a lush, tropical aesthetic to any garden with minimal effort.
The Botanical Truth: Rhizome vs. Bulb
In the world of gardening, "bulb" is often used as a catch-all term for any plant that grows from a fleshy underground storage organ. However, if you look closely at a canna, you will see it is technically a rhizome.
A true bulb, like a tulip or an onion, is made of modified leaf layers that protect a miniature flower bud inside. A rhizome, on the other hand, is a thickened underground stem that grows horizontally just beneath the soil surface. If you have ever handled a piece of fresh ginger from the grocery store, you have held a rhizome.
Cannas use these thick stems to store energy, water, and nutrients. This storage system allows them to grow incredibly fast once the weather warms up. While we may call them "canna bulbs" for convenience, knowing they are rhizomes helps you understand how to plant and divide them. For more background, see this guide to growing and overwintering perennial canna bulbs.
Each rhizome features several "eyes" or nodes. These are small, pointed bumps where the new shoots will eventually emerge. When you choose your plants, look for rhizomes that feel firm and heavy for their size. A healthy rhizome is the foundation for a vigorous plant.
The History and Origin of Cannas
Cannas are native to the tropical and subtropical regions of the Americas. They can be found growing wild from the southern United States all the way down through Argentina. Because they originated in warm climates, they have evolved to thrive in heat and humidity.
In their native habitats, they often grow near water. This explains why they are much thirstier than many other summer-flowering plants. While they are now grown all over the world, they still carry that tropical DNA. This makes them perfect for the hot, humid summers common in many parts of the US.
Interestingly, cannas are not actually lilies. They are more closely related to ginger, bananas, and birds of paradise. You can see this relationship in their large, lush leaves and the way their stems unfurl. The name "canna" comes from the Latin word for a reed or cane, referring to their sturdy, upright stems.
Anatomy of a Canna Plant
To truly understand what these plants are, it helps to look at them from the ground up. Every part of the canna is designed for a bold presence in the garden.
The Underground Rhizome
The rhizome is the powerhouse of the plant. It stays dormant during the winter and springs to life when the soil temperature rises. At our Longfield Gardens facility, we ensure our rhizomes are handled carefully to preserve the "eyes." The more eyes a rhizome has, the more stems it will produce, leading to a fuller, more impressive plant.
The Foliage
For many gardeners, the leaves are just as important as the flowers. Canna leaves are massive and can reach up to two feet long. Depending on the variety, the foliage may be a classic deep green, a rich burgundy, or even variegated with stripes of yellow, white, and orange. Varieties like 'Phasion' (often called Tropicanna) are famous for their multicolored leaves that glow when the sun shines through them.
The Stems and Flowers
The stems are solid and cane-like, allowing the plant to stand tall even in moderate winds. At the top of these stems, the flowers emerge in clusters. Canna flowers are asymmetrical and come in brilliant shades of red, orange, yellow, and pink. Some even have speckled patterns.
The "petals" of a canna flower are not actually petals at all. They are highly modified stamens called staminodes. This unique botanical structure gives the flowers their ruffled, exotic appearance.
Key Takeaway: Cannas are tropical rhizomes related to bananas and ginger. They are prized for their dramatic foliage and brilliant, orchid-like blooms that thrive in summer heat.
Why Canna Bulbs are Essential for Summer Gardens
If you are looking for a plant that works hard all season, the canna is a top contender. Here are a few reasons why they are a favorite for us and our customers.
They Provide Instant Privacy
Tall varieties of cannas, such as 'Red King Humbert' or 'Wyoming', can grow 6 to 8 feet tall in a single season. This makes them an excellent choice for creating a "living fence." You can plant a row of them along a patio or property line to create a private, lush sanctuary in just a few months.
They Attract Pollinators
Hummingbirds absolutely love canna flowers. The bright colors and tubular shapes are perfectly designed for their long beaks. If you want to bring more wildlife into your garden, planting a few cannas is one of the easiest ways to do it. You may also see butterflies and bees visiting the blooms throughout the day.
They Thrive Where Others Struggle
Many flowering plants wilt in the intense heat of July and August. Cannas are the opposite; they love the heat. As long as they have enough water, they will continue to grow and bloom when the rest of the garden looks tired. They are also one of the few decorative plants that can tolerate "wet feet," meaning they grow well in soggy soil or at the edge of a pond.
Understanding Sizes: From Dwarf to Giant
When deciding which canna bulbs to buy, size is an important factor. There is a canna for almost every space, but you need to match the variety to your available room.
- Dwarf Cannas: These varieties typically grow between 2 and 3 feet tall. They are perfect for the front of a flower bed or for growing in containers. They offer all the color of larger types without taking over the space. 'Lucifer' is a well-known dwarf variety with bright red flowers edged in yellow.
- Medium Cannas: Growing 3 to 5 feet tall, these are the workhorses of the perennial border. They fit perfectly in the middle of a bed, providing a beautiful backdrop for shorter annuals.
- Tall/Giant Cannas: These are the showstoppers. Reaching 6 to 8 feet (or even taller in ideal conditions), these varieties need space. They are best used at the back of a border or as a focal point in the landscape.
Foliage Patterns and Colors
One of the most exciting things about cannas is the diversity of their leaves. While many plants are grown only for their flowers, a canna provides visual interest even when it isn't blooming.
- Solid Green: Varieties like 'The President' have lush, emerald green leaves that provide a clean, classic look. This foliage makes the bright red flowers pop.
- Bronze and Burgundy: 'Wyoming' and 'Red King Humbert' feature dark, smoky foliage. These dark leaves create a beautiful contrast with other green plants in your garden and make orange or red flowers look even more intense.
- Variegated and Striped: 'Pretoria' (also known as Bengal Tiger) is famous for its yellow and green striped leaves. These varieties act like a beacon in the garden, drawing the eye even from a distance.
Simple Tips for Choosing the Best Spot
Getting the right plant in the right place is the most important rule of gardening. For cannas, "the right place" usually involves two things: sun and water.
Sun Requirements
Cannas are sun worshippers. To get the best foliage color and the most flowers, they need at least 6 to 8 hours of direct sunlight every day. If they are planted in too much shade, they will become "leggy," meaning the stems will be thin and weak as they stretch toward the light. They may also fail to bloom. For more guidance, read these canna sunlight tips.
Soil and Drainage
While cannas love water, they still prefer soil that is rich in organic matter. If your soil is very sandy, adding compost will help hold onto moisture. If you have heavy clay, the rhizomes will appreciate being planted in a spot that doesn't stay completely underwater during a winter freeze, though during the summer growing season, they are very tolerant of damp conditions.
Water and Fertilizer
Think of cannas as the "marathon runners" of the garden. They use a lot of energy to grow so large in such a short time. This means they are very thirsty. During the heat of the summer, you may need to water them several times a week. They are also heavy feeders. Applying a balanced liquid fertilizer once a month will help them stay vibrant and continue producing new flower spikes.
What to Do Next:
- Check your garden for a spot that gets 6+ hours of sun.
- Ensure the area has easy access to a hose or watering can.
- Mix some compost or aged manure into the soil before planting.
- Choose a mix of tall and dwarf varieties for a layered look.
Planting Your Canna Rhizomes
Once you have your rhizomes and have picked your spot, the actual planting process is very straightforward. Unlike some delicate seeds, cannas are quite hardy and easy to handle.
When to Plant
The most important thing to remember is that cannas do not like the cold. You should wait to plant them outdoors until the soil has warmed up and all danger of frost has passed. In most regions, this is late May or early June. If you want a head start, you can plant them in pots indoors about a month before the last frost and then move them outside once it is warm. See this canna planting timing guide for more detail.
How Deep and How Far Apart?
Dig a hole about 2 to 3 inches deep. Lay the rhizome in the hole horizontally. It doesn't matter which way the "eyes" are pointing, as the plant will figure out which way is up, but pointing them toward the sky can give them a slight head start.
Space dwarf varieties about 1 foot apart. For taller varieties, give them 2 feet of space. They may look small when you first plant them, but they will fill that space quickly!
Growing Cannas in Containers
If you don't have a lot of garden space, or if your soil isn't ideal, containers are a fantastic option. A single tall canna in a large pot creates a sophisticated, architectural look on a porch or deck. For additional advice, see how to grow canna bulbs in containers.
When growing in pots, keep these three rules in mind:
- Pot Size: Use a large, heavy pot. Tall cannas can become top-heavy, and a small pot might tip over in the wind. A pot that is at least 15 to 18 inches in diameter is a good starting point.
- Drainage: Make sure the pot has drainage holes. While cannas like moisture, you don't want the rhizome to sit in stagnant, stinky water at the bottom of a sealed pot.
- Watering: Containers dry out much faster than the ground. In the height of summer, a container-grown canna might need water every single day.
The Life Cycle: Understanding Dormancy
To understand what a canna bulb is, you have to understand its yearly cycle. In tropical climates, cannas grow year-round. In the United States, their life cycle is dictated by the seasons.
Summer Growth
From June through September, the plant is in its active phase. It will continuously produce new leaves and flower spikes. As old flowers fade, you can "deadhead" them (cut off the spent flower head). This encourages the plant to put its energy into making new blooms rather than seeds.
Autumn Transition
When the first frost hits, the foliage will turn black and die back. This is a natural part of the process. The plant isn't dead; it is simply moving its energy back down into the rhizome for the winter.
Winter Rest
This is where your location matters.
- In Warm Zones (Zones 9-10): You can leave the rhizomes in the ground. Just cut the dead stalks down to a few inches above the soil. They will sprout again in the spring.
- In Cooler Zones (Zones 3-8): The ground will freeze deep enough to kill the rhizome. In these areas, you must "lift" the rhizomes. Dig them up, let them dry slightly, and store them in a cool, dark, frost-free place (like a basement or garage).
Troubleshooting Common Canna Questions
While we want gardening to be a source of joy, it is helpful to know what to do if things don't go exactly as planned. Most canna issues are very easy to solve with simple adjustments.
My Canna Isn't Blooming
The most common reason for a lack of flowers is a lack of sun. If your plant is in the shade, it will focus all its energy on trying to grow taller to find light, leaving nothing for flowers. Another reason could be a lack of nutrients. Try adding a bit of fertilizer to give the plant the boost it needs.
Holes in the Leaves
If you see small holes in the leaves, you likely have slugs or snails. These pests love the tender, juicy leaves of young cannas. The easiest fix is to keep the area around the base of the plants clear of debris where slugs like to hide. You can also use a simple copper barrier or a pet-safe slug bait if they become a real nuisance.
The Leaves Look "Rolled"
In some parts of the US, a small caterpillar called a "leaf roller" can be found. They use silk to pull the edges of a leaf together into a tube. While they rarely kill the plant, they can make the leaves look messy. You can simply unroll the leaf and remove the caterpillar by hand or use a gentle horticultural spray if the infestation is large.
Using Cannas in the Landscape
Because of their height and texture, cannas are incredibly versatile. Here are a few ways we like to use them:
- The Mixed Border: Place cannas behind shorter perennials like daylilies or coneflowers. The broad leaves of the canna provide a beautiful contrast to the finer textures of other garden plants.
- The Tropical Corner: Combine cannas with other large-leafed plants like elephant ears or hibiscus. This creates a dense, jungle-like feel that is very relaxing.
- Water Features: If you have a backyard pond, you can actually grow some varieties of canna in the shallow water at the edge. They help filter the water and look stunning reflected in the surface.
Safety for Pets and Children
When adding new plants to your garden, it is always wise to consider safety. The good news is that Canna indica is generally considered non-toxic to dogs, cats, and horses by the ASPCA. In fact, in some cultures, the rhizomes of certain canna species are used as a source of starch for food.
However, as with any garden plant, it is best to discourage pets or children from chewing on them. The large leaves and thick stems are not meant for consumption and could cause a mild stomach upset if eaten in large quantities. Keeping your garden a place for looking and smelling rather than tasting is always the safest approach.
Conclusion
At Longfield Gardens, we want you to feel confident and excited about your garden. Understanding that canna bulbs are actually powerful, heat-loving rhizomes is the key to unlocking their potential. These plants offer so much more than just a flower; they provide structure, privacy, and a sense of tropical wonder that few other plants can match.
By giving them plenty of sun, a regular drink of water, and a little bit of food, you can transform a plain backyard into a vibrant oasis. Gardening should be a rewarding experience, and cannas are the perfect partner for achieving big results with simple care.
Next Steps for Your Garden:
- Browse our selection of canna varieties at Longfield Gardens to find your favorite colors.
- Plan your planting layout, putting tall varieties in the back and shorter ones in the front.
- Order your rhizomes in early spring so they arrive ready for the warming soil.
- Get your shovel ready and prepare for a summer filled with tropical beauty.
FAQ
Are canna bulbs the same as lilies?
Despite being commonly called "canna lilies," they are not true lilies. True lilies belong to the Lilium genus, while cannas are part of the Canna genus. They are actually more closely related to bananas and ginger, which is evident in their large, paddle-shaped leaves and thick rhizomes.
Can I leave my canna bulbs in the ground during the winter?
This depends entirely on your USDA hardiness zone. If you live in a warm climate (Zones 9-10), you can leave them in the ground year-round. In colder regions (Zones 3-8), the freezing temperatures will kill the rhizomes, so you should dig them up in the fall and store them in a frost-free place until spring.
How much sun do canna bulbs need to grow?
Cannas are sun-loving tropical plants that perform best when they receive at least 6 to 8 hours of direct sunlight every day. While they can grow in partial shade, they will produce fewer flowers and the foliage colors may not be as vibrant. Sunlight is the "fuel" that allows them to grow so tall so quickly.
Why are my canna leaves turning brown at the edges?
Brown edges on canna leaves are usually a sign of "thirst." Because cannas have such large leaves, they lose water very quickly through evaporation. If the soil stays dry for too long, the edges of the leaves will begin to crisp. Increasing your watering frequency during hot, dry spells usually solves this issue.
