Table of Contents
- Introduction
- Understanding the Canna Rhizome
- Key Physical Characteristics
- Identifying Growth Points or "Eyes"
- Telling the Top from the Bottom
- Distinguishing Health from Concern
- Variation Between Varieties
- Preparing Your Rhizomes for the Garden
- Growing with Confidence
- Conclusion
- FAQ
Introduction
There is a unique sense of excitement that comes with the arrival of a package of summer bulbs. Opening that box and seeing the potential for a tropical paradise right in your own backyard is one of the true highlights of the gardening season. At Longfield Gardens, we want to make sure you feel confident from the moment you unpack your order. For Shipping Information, check the details before your plants arrive.
In this guide, we will focus specifically on identifying and evaluating canna lilies. While they are often called "bulbs," these plants have a very distinct appearance that sets them apart from tulips or daffodils. We will explain how to recognize a healthy specimen, how to tell which way is up, and what to expect when you look closely at these tropical powerhouses. By understanding the physical characteristics of these plants, you can ensure they get the best possible start in your garden.
Understanding the Canna Rhizome
The first thing to know about canna lilies is that they do not grow from a "true bulb" like an onion or a lily. Instead, they grow from a structure called a rhizome. If you have ever seen a hand of fresh ginger in the grocery store, you already have a great mental image of what a canna lily looks like. For more background, see All About Cannas.
A rhizome is essentially a thick, fleshy underground stem that grows horizontally just beneath the soil surface. Its job is to store energy and water for the plant so it can produce those massive, lush leaves and vibrant flowers during the heat of the summer. Because they are storage organs, healthy cannas should feel heavy and substantial for their size.
When you look at a canna rhizome, you will notice it is not perfectly round or symmetrical. It is a knotty, irregular shape with various bumps and ridges. This unique structure is what allows the plant to spread and create those impressive clumps of foliage that we love in the summer landscape.
Key Physical Characteristics
When you hold a canna lily rhizome, you will notice several specific features. Understanding these will help you identify them easily among other summer-blooming plants.
The Shape and Texture
Canna rhizomes are generally oblong or finger-like. They often arrive as a single "division," which looks like a thick, lumpy segment of a root. The texture of the skin is somewhat similar to a potato—it is relatively thin and can be slightly papery or smooth depending on how recently it was harvested.
Underneath that skin, the rhizome is very firm. When you squeeze a healthy one, it should have very little "give." It should feel like a crisp carrot or a firm potato. If the rhizome feels light, hollow, or like a dried-out sponge, it may have lost too much moisture during storage.
The Color Palette
The color of a canna lily rhizome can vary depending on the variety of the plant. Most common varieties with green leaves will have rhizomes that are a creamy bone color, light tan, or beige.
However, if you are planting varieties with dark, dramatic foliage—such as the deep burgundy leaves of 'Australia'—the rhizome itself may reflect those pigments. It is common to see reddish, purple, or bronze tints on the skin of these varieties. This is perfectly normal and is a great way to tell your varieties apart if you happen to mix them up during planting.
Size and Weight
Size can vary significantly based on the cultivar. Some dwarf cannas produce smaller, more compact rhizomes, while giant varieties can produce very large, heavy segments. Regardless of the length, the thickness is usually between one and three inches. A larger rhizome typically contains more stored energy, which often leads to a faster start once the soil warms up.
Key Takeaway: A healthy canna rhizome looks like a firm, chunky piece of ginger. It should be heavy for its size and have a color ranging from creamy white to dark bronze depending on the variety.
Identifying Growth Points or "Eyes"
The most important feature to look for on your canna rhizome is the "eye." Much like the eyes on a potato, these are the points where the new stems and leaves will emerge.
What Do the Eyes Look Like?
On a dormant rhizome, the eyes look like small, rounded bumps or pointed "nubs" along the surface. They are usually concentrated at the ends of the rhizome or along the upper side.
If the rhizome has already started to wake up from dormancy, these eyes may have developed into short, pointed sprouts. These sprouts are often white, light green, or even pinkish-red at the tips. Do not worry if these sprouts look a bit pale; they are simply waiting for sunlight to begin producing chlorophyll.
How Many Eyes Should There Be?
Most healthy divisions will have between two and five eyes. More eyes generally mean more stems, which results in a fuller, bushier plant. However, even a rhizome with a single strong eye is capable of growing into a beautiful, flowering plant. As the plant grows throughout the summer, it will naturally produce more rhizome segments and more eyes underground.
Handling the Eyes
The eyes are the most delicate part of the plant. While the main body of the rhizome is quite tough, the emerging sprouts can be snapped off if handled roughly. If a sprout does break off, do not panic. The rhizome usually has "secondary" eyes that can take over, though it might take the plant a little longer to get started.
Telling the Top from the Bottom
One of the most common questions we hear is, "Which way do I plant this?" Because cannas are irregular in shape, it can sometimes be confusing to figure out the correct orientation.
Identifying the Top
Look for the eyes or the sprouts. These are the parts of the plant that want to reach for the sun, so they should always be facing upward. You may also see a "stem scar"—a circular, flat area where last year's stalk was cut away. This scar should also face up or toward the side.
Identifying the Bottom
The bottom of the rhizome is often flatter and may have the remains of old, dried roots from the previous growing season. These roots will look like thin, brown, hair-like fibers. They are no longer active, but they serve as a helpful landmark. New roots will eventually grow from the underside of the rhizome and from the base of the new sprouts.
The Side-Planting Rule
If you are truly unsure which side is the top, the safest bet is to plant the rhizome on its side. For a full walkthrough, see How to Plant Canna Lily Bulbs in the Ground.
What to Do Next:
- Carefully inspect each rhizome for at least one firm, healthy eye.
- Identify the "up" side by looking for sprouts or stem scars.
- If the orientation is confusing, simply lay the rhizome flat on its side.
- Keep the rhizomes in a cool, dry place until you are ready to plant.
Distinguishing Health from Concern
When you receive your plants from us at Longfield Gardens, they are carefully inspected to ensure they meet our quality standards. However, because they are living things that have been in a dormant state, they may not always look "pretty." It is important to know the difference between a natural appearance and a potential issue.
Surface Mold
It is very common to see a small amount of "storage mold" on summer bulbs. This often looks like a light dusting of blue or white powder on the surface of the skin. This is a result of the moisture held within the fleshy rhizome and the lack of airflow in a shipping box.
In almost all cases, this mold is harmless. Once the rhizome is planted in the soil, the natural soil microbes will take over, and the storage mold will disappear. You can simply wipe it off with your finger or leave it as is; it will not affect the growth of your flowers.
Wrinkled Skin
Because cannas are harvested and then stored for a period before shipping, they may lose a small amount of surface moisture. This can cause the skin to look slightly wrinkled or shriveled. As long as the rhizome still feels firm and heavy when you squeeze it, a few wrinkles are nothing to worry about. Think of it like a slightly older apple—the inside is still perfectly good.
Old Roots and Soil
You may see dried-out, stringy bits attached to the rhizome. These are the roots from last year. They are completely normal and do not need to be trimmed off, although you can if you prefer a tidier look. You might also find a small amount of peat moss or soil clinging to the ridges; this is just a sign of the healthy environment the plant was grown in.
When to Be Concerned
The main sign of a problem is softness. If a rhizome feels "mushy" like a rotten tomato, or if it crumbles when you give it a gentle squeeze, it is likely no longer viable. Similarly, a very foul, pungent odor (beyond a normal earthy smell) can indicate rot. If you encounter a rhizome that is dark brown or black all the way through and feels soft, please contact our customer service team.
Variation Between Varieties
Not all canna lilies look identical. At Longfield Gardens, we offer a variety of types, and their rhizomes can reflect their unique characteristics.
Dwarf vs. Standard
Dwarf cannas are bred to stay shorter, usually topping out at two to three feet. Their rhizomes are often more compact and "tighter" in appearance.
Standard cannas, which can reach heights of five or six feet, tend to produce longer, more robust rhizomes with more space between the eyes.
Foliage Color and Rhizome Pigment
As mentioned earlier, the color of the foliage is often hinted at in the rhizome.
- Green Foliage: These typically have the lightest-colored rhizomes (beige or ivory).
- Bronze or Purple Foliage: These often have darker skin with purple or reddish tones.
- Variegated Foliage: Sometimes these rhizomes have a mottled appearance or a "striped" look to the skin texture.
Preparing Your Rhizomes for the Garden
Once you have identified that your rhizomes are healthy and you know which way is up, you are ready to get started. While cannas love the heat, they are sensitive to cold, so timing is everything.
Waking Them Up
If you live in a northern climate with a short growing season, you can "wake up" your cannas indoors about four to six weeks before the last frost. For a head start, see How to Start Planting Canna Bulbs Indoors.
Checking Temperature
Cannas are tropical plants. They do not like cold soil. Wait to plant them in the ground until the soil temperature has reached at least 60°F. If you plant them too early in cold, wet soil, they may sit dormant for a long time or struggle to get started. If you need help with timing, check the Hardiness Zone Map.
Soil and Moisture
When you look at the chunky, moisture-storing rhizome, it tells you a lot about what the plant needs. Those thick structures are built to support a plant that grows very quickly and produces huge leaves. This means cannas are "hungry" and "thirsty." They perform best in soil that is rich in organic matter and stays consistently moist. Unlike many other bulbs that prefer to dry out, cannas can even handle "wet feet" and are often used in the margins of water gardens.
Key Takeaway: The physical structure of the canna rhizome is designed for rapid growth and water storage. Provide them with rich soil, plenty of water, and warm temperatures to see them reach their full potential.
Growing with Confidence
Gardening should be a rewarding experience, not a source of stress. When you look at a canna lily rhizome, remember that it is a powerhouse of energy. It is designed by nature to be resilient and vigorous. Even if it looks a little strange or knotty, that rhizome contains everything the plant needs to produce a spectacular show of color.
By focusing on the basics—checking for firmness, identifying the eyes, and waiting for the right soil temperature—you are setting yourself up for success. We take great pride in the quality of the plants we ship from Longfield Gardens, and we stand behind them with our 100% Quality Guarantee. If you ever have a question about how your plants look upon arrival, we are here to help you move forward with confidence.
Conclusion
Understanding what a canna lily bulb looks like is the first step in creating a vibrant, tropical-inspired garden. These thick, ginger-like rhizomes are fascinating structures that hold the secret to some of the most dramatic flowers and foliage in the summer landscape. By looking for firm texture, identifying the growth eyes, and recognizing the natural variations in color, you can plant with the assurance that your garden will thrive.
- Rhizomes are thick, fleshy, and firm, similar to ginger root.
- Identify the "eyes" as small bumps or pointed sprouts to determine where growth will begin.
- Plant in warm soil (at least 60°F) for the best results.
- Don't worry about light surface mold or a few wrinkles; these are normal for dormant plants.
We are excited to help you bring a touch of the tropics to your home. For more tips on planning your summer garden or to browse our canna collection, feel free to explore our other guides and collections.
"The chunky, irregular shape of a canna rhizome is nature's way of storing the immense energy needed to produce a six-foot-tall tropical masterpiece in just one season."
FAQ
Is it a bulb or a rhizome?
While many people refer to them as canna lily bulbs, they are technically rhizomes. A rhizome is a horizontal underground stem that stores energy, whereas a true bulb (like a tulip) has layers of fleshy scales.
What if my canna rhizome has no sprouts when it arrives?
That is perfectly normal. Many rhizomes are shipped in a fully dormant state. As long as the rhizome feels firm and you can see small bumps (eyes), it will sprout once it is planted in warm soil and given moisture.
Which way is up when planting a canna lily?
The "up" side is the one with the most visible eyes, sprouts, or old stem scars. If you cannot tell which side is which, simply plant the rhizome on its side; the plant will naturally grow toward the surface. For more help, see Canna Lily Bulbs Which Way Up? Simple Planting Guide.
Should I be worried if the rhizome is a different color than the picture?
No, rhizome color varies by variety. Plants with green leaves usually have tan or cream-colored rhizomes, while plants with dark burgundy or bronze leaves often have rhizomes with reddish or purple pigments.