Introduction
There is nothing quite like the vibrant, tropical energy that canna lilies bring to a summer garden. With their massive, paddle-shaped leaves and brilliant blooms, these plants transform a standard backyard into a lush getaway. If you have recently brought home your first set of cannas, you might be looking at the knobby, root-like structures and wondering where to start. At Longfield Gardens, we want to make sure your gardening experience is as rewarding and simple as possible.
This guide is designed for home gardeners who want to take the guesswork out of planting canna lilies. We will focus specifically on how to identify the correct orientation for your canna "bulbs" (which are actually rhizomes) and how to set them up for a season of spectacular growth. Whether you are planting them in large patio pots or directly in your garden beds, getting the direction right is the first step toward success.
We will cover how to spot the growing points, why planting depth matters, and how to handle a rhizome that seems to have no clear "top." Understanding the anatomy of these tropical beauties ensures they sprout quickly and grow into the show-stopping centerpieces they are meant to be.
Understanding Canna Rhizomes
Before we talk about which way is up, it is helpful to know what you are actually holding. While most people call them "canna lily bulbs," they are technically rhizomes. A rhizome is a thick, fleshy underground stem that grows horizontally just beneath the soil surface. Unlike a tulip or daffodil bulb, which has a very clear pointed top and a flat bottom, a canna rhizome looks more like a piece of ginger root.
These fleshy stems act as a storage unit for the plant. They hold all the energy and nutrients the canna needs to send up those massive leaves and stalks. Because they are stems rather than true bulbs, they grow differently. Instead of growing from a single central point, they have multiple "eyes" or buds along the length of the rhizome. Each of these eyes has the potential to become a new stalk.
This horizontal growth habit is why you will often see cannas spreading out into a beautiful, dense clump over time. When you understand that you are planting a horizontal stem rather than a vertical bulb, the "which way up" question becomes much easier to answer.
How to Identify the Top of the Rhizome
When you take your canna rhizomes out of their packaging, they may look a bit mysterious. However, there are three main clues you can look for to figure out which side should face the sky.
Look for the "Eyes"
The most important things to look for are the eyes. These are small, rounded bumps or points on the surface of the rhizome. They often look like the "eyes" on a potato. Sometimes they are just small, firm nubs, and other times they might already be starting to sprout into a pale green or white point.
These eyes are the future stalks of your canna lily. For the fastest growth, you want these points to be facing upward or toward the soil surface. This gives the new shoots the shortest and most direct path to the sunlight.
Identify the Old Stem Stump
Most canna rhizomes will have a noticeable "stump" from the previous year’s growth. This looks like a circular, woody, or dried-out area where the main stalk was cut away after the last growing season.
This stump is a guaranteed indicator of which way was "up" last year. While the eyes represent future growth, the stump represents the past. When you plant, the side with the old stem stump should be facing upward.
Check the Root Side
The bottom of the rhizome is usually flatter and may have some dried, stringy bits attached to it. These are the old roots. While new roots will eventually grow from all over the rhizome once it is in the ground, the presence of old root debris can help you identify the underside. If one side is covered in these dried fibers and the other side has smooth nubs or a stem stump, the fiber-covered side goes down.
Key Takeaway: To find the top of a canna rhizome, look for the small, pointed "eyes" or the woody stump of last year's stalk. These should always face upward toward the light.
Canna Lily Bulbs: Which Way Up?
Now that you know what to look for, the actual placement is very simple. In most cases, you will be planting the rhizome horizontally.
The Horizontal Approach
Because cannas are underground stems, they naturally prefer to lie flat. Think of it like laying a log on the ground rather than standing it up on its end. When you place the rhizome horizontally in the planting hole, you allow the different eyes along the length of the stem to grow upward at the same time. This results in a fuller, bushier plant with more stalks.
If your rhizome is long and has eyes at both ends, laying it flat is the best way to ensure all those eyes can reach the surface easily.
What if it's Vertical?
Sometimes a rhizome is shaped in a way that makes horizontal planting feel awkward. If you have a rhizome where all the eyes are clustered at one end, you can plant it at a slight angle. The most important rule is that the eyes must be pointing up or sideways—never directly down toward the bottom of the hole.
Dealing with "Mystery" Rhizomes
Occasionally, you might find a rhizome that is so smooth or rounded that you cannot find any eyes or stumps. If you truly cannot tell which way is up, don't worry. The best approach in this situation is to lay the rhizome on its side.
Plants have a natural ability to sense gravity and light. Even if a canna is planted upside down, the new shoots will eventually sense the warmth of the sun and the pull of gravity and grow around the rhizome to reach the surface. It might take the plant a week or two longer to appear above the soil, but it will still grow into a healthy plant.
What to do next:
- Unpack your rhizomes as soon as they arrive.
- Inspect each piece for at least one "eye" or a stem stump.
- If you see any soft spots, trim them away and let the cut air-dry for a day before planting.
- Lay the rhizome horizontally in your hand to get a feel for how it will sit in the soil.
Planting Depth and Spacing
Once you have identified the right orientation, the next step is getting the depth and spacing correct. This is one of the most important "quiet winners" in gardening. If you plant too deep, the plant might struggle to reach the surface. If you plant too shallow, the tall stalks might tip over once they reach their full height. For additional guidance, see this canna planting depth and sprouting guide.
The Magic Depth
For most canna lilies, the ideal planting depth is 4 to 6 inches deep. This means there should be about 4 inches of soil covering the top of the rhizome. This depth provides enough weight to anchor the plant as it grows 4, 5, or even 6 feet tall. It also keeps the rhizome insulated from the fluctuating temperatures of early spring.
Giving Them Space
Cannas are big plants with big appetites for sun and nutrients. They also spread as the rhizomes grow underground.
- Tall varieties: Space these about 2 feet apart.
- Dwarf or compact varieties: Space these about 1 foot apart.
If you are planting in containers, you can be a bit more crowded for a lush "instant" look, but generally, one large rhizome per 12-inch pot is a good rule of thumb. This container spacing guide for cannas provides additional help.
Right Plant, Right Place
Cannas are tropical plants, which means they have very specific needs when it comes to their environment. Following the "right plant, right place" rule will make your gardening much easier.
Sun is Non-Negotiable
To get the best flowers and the most vibrant foliage, cannas need full sun. This means at least 6 to 8 hours of direct, unfiltered sunlight every day. If they are planted in too much shade, they will become "leggy," meaning the stalks will be thin and weak as they stretch for the light. They may also fail to bloom entirely. Read more about growing cannas in full sun.
Drainage Basics
Drainage describes how fast water leaves the soil. Cannas love moisture, but they do not like to sit in a "puddle." If the soil stays soggy for days at a time, the rhizomes can rot before they even have a chance to sprout.
- In the garden: Choose a spot where water doesn't pool after a heavy rain.
- In pots: Always use a container with drainage holes at the bottom.
If your soil is heavy clay, you can improve the drainage by mixing in some organic matter like compost or shredded bark. This creates more "air space" in the soil, allowing water to move through while still keeping the roots hydrated.
Timing Beats Tricks
When it comes to cannas, patience is a virtue. Because they are tropical, they are very sensitive to cold temperatures. Planting them too early in cold, wet soil is a common reason for slow starts.
The 60-Degree Rule
The best time to plant canna lilies outdoors is when the soil temperature has reached at least 60°F. In most parts of the US, this is usually a few weeks after the last frost date in the spring. If the air is warm enough for you to wear a T-shirt comfortably all day, it is usually warm enough for cannas.
Starting Early Indoors
If you live in a northern climate with a short summer, you might want to "jumpstart" your cannas. We often recommend starting them in pots indoors about 4 to 6 weeks before the last frost.
- Plant the rhizome in a pot with potting soil.
- Place it in a warm, sunny window.
- Water sparingly until you see the first green sprout.
- Move the whole pot outside (or transplant into the garden) once the weather is consistently warm.
Starting them indoors allows you to enjoy flowers much earlier in the season. Watching those first tightly rolled leaves unfurl inside your home is an exciting way to welcome the spring.
Water Correctly, Not Constantly
Watering is where many gardeners feel unsure, but the rule for cannas is simple: "deep, then let it dry a bit."
Establishing Your Plants
When you first plant your rhizomes, give them a good drink of water to settle the soil. After that, wait until you see green growth appearing above the soil before you start watering regularly. A dormant rhizome without leaves cannot "drink" much water, and keeping the soil too wet at this stage can lead to rot.
Growing Season Hydration
Once the plants are growing vigorously and the summer heat sets in, cannas become very thirsty. They have large leaves that lose moisture quickly. During the peak of summer, you may need to water them every few days. If the leaves start to roll up tightly like a cigar, the plant is telling you it needs a drink.
In sandy soil, you will need to water more often because the water drains away quickly. In heavier soil, you can wait longer between waterings.
Key Takeaway: Wait for the first green shoots to appear before you start a regular watering schedule. Once established, cannas love consistent moisture but hate standing in water.
Simple Troubleshooting
If your cannas aren't performing the way you expected, don't worry. Most issues can be solved by looking at a few basic factors.
"My cannas haven't sprouted yet."
Cannas can be slow to wake up. It often takes 3 to 4 weeks for the first shoot to appear. If it has been longer than that, check the soil temperature. If the ground is still cool, they are simply waiting for more warmth. Ensure they aren't buried too deep; if they are deeper than 6 inches, it just takes them longer to reach the surface.
"The leaves are green, but there are no flowers."
This is usually a light issue. If a canna isn't getting at least 6 hours of direct sun, it will focus all its energy on leaves and skip the flowers. Another possibility is that the plant needs a bit of food. A balanced, slow-release fertilizer applied in early summer can give the plant the boost it needs to produce blooms.
"Something is eating holes in the leaves."
Canna leaf rollers (caterpillars) are the most common pest. They roll themselves up in the new leaves before they unfurl. You can often simply unroll the leaf and remove the caterpillar by hand. Keeping your garden clean of debris at the end of the season also helps reduce pest issues for the following year.
Fall Care and Storage
In USDA zones 8 through 11, canna lilies are generally hardy. This means you can leave them in the ground all year long. You can simply cut the foliage back to the ground after it turns brown in the fall and cover the area with a layer of mulch to protect the rhizomes.
However, if you live in zones 3 through 7, the ground will freeze deep enough to kill the rhizomes. In these areas, you treat cannas like a summer annual, or you "lift" them to store indoors.
How to Lift and Store
- Wait for the first frost to blacken the foliage.
- Cut the stalks down to about 4 inches.
- Carefully dig up the clump of rhizomes.
- Gently shake off the excess soil (no need to wash them).
- Let them air-dry in a garage or shed for a few days.
- Store them in a cardboard box filled with peat moss or wood shavings.
- Keep the box in a cool, dark, frost-free place (like a basement) until spring.
The Joy of Canna Varieties
One of the best parts of growing cannas is the incredible variety available. We work with trusted growers to ensure that the rhizomes you receive are healthy and true to variety.
If you love bold colors, look for varieties like 'Red King Humbert', which features dark, bronze-toned leaves and bright scarlet flowers. For something more architectural, 'Pretoria' (also known as 'Bengal Tiger') has stunning yellow and green striped leaves that look beautiful even when the plant isn't in bloom. Learn more about Bengal Tiger, also known as Pretoria.
If you have a smaller space, short cannas are a perfect choice. They stay under 3 feet tall but still produce the same large, tropical flowers as their taller cousins. They are particularly well-suited for containers on a porch or balcony.
Conclusion
Planting canna lilies is a straightforward and rewarding way to bring a touch of the tropics to your home. By identifying the eyes or the old stem stump, you can ensure you are placing your rhizomes in the best position for growth. Remember that while "eyes up" is the goal, these plants are resilient and will usually find their way to the light even if you make a small mistake.
At Longfield Gardens, we are committed to helping you succeed. We stand behind the quality of our bulbs and rhizomes with a 100% quality guarantee. If your items arrive damaged or don't perform as expected in their first season, we are here to help with a replacement or credit. Gardening should be an enjoyable journey, and we are happy to provide the support you need along the way.
Next Steps for Success:
- Check your local frost dates to plan your planting timing.
- Select a spot in your garden that gets at least 6 hours of full sun.
- Prepare your soil with a little compost if it feels heavy or compacted.
- Order your favorite varieties early to ensure you get the best selection for the season.
"The secret to beautiful cannas isn't a complex trick; it is simply matching the plant's love for sun and warmth with a well-drained spot in your garden."
FAQ
What happens if I plant my canna lily rhizome upside down?
If you plant a canna rhizome upside down, the plant will still grow, but it will take a little longer to appear above the soil. The new shoots will naturally sense gravity and turn themselves upward to find the light. While "eyes up" is ideal for faster growth, the plant is resilient enough to correct itself.
How long does it take for cannas to sprout after planting?
Cannas are relatively slow starters and usually take 3 to 4 weeks to show their first green shoots. This timeline depends heavily on the soil temperature. If the soil is consistently 60°F or warmer, they will sprout faster than if they are planted in cool, early-spring soil.
Do I need to soak canna rhizomes before planting?
Soaking is not strictly necessary, but some gardeners find it helps "wake up" the rhizome. If you choose to soak them, place them in a bowl of lukewarm water for about 2 to 4 hours just before planting. Avoid soaking them for too long, as this can lead to rot.
Can I grow canna lilies in pots instead of the ground?
Yes, cannas thrive in containers! Ensure you use a large pot (at least 12 inches in diameter) with good drainage holes. Use a high-quality potting mix rather than garden soil, and remember that container plants will need to be watered more frequently than those in the ground, especially during hot summer weeks. For more ideas, see these tips for growing cannas in containers.
