Can Canna Lily Grow in Water?

Table of Contents

1. Introduction
2. Yes, You Can Grow Canna Lilies in Water
3. The Difference Between Land and Water Cannas
4. How to Transition Cannas to a Water Garden
5. Best Practices for Planting Cannas in Ponds
6. Choosing the Best Varieties for Water Planting
7. Caring for Cannas in a Water Environment
8. Overwintering Water-Grown Canna Lilies
9. Creating a Lush Water Garden Landscape
10. Troubleshooting Common Issues
11. Conclusion
12. FAQ

Introduction

There is something undeniably magical about the sight of lush, tropical foliage rising elegantly out of a garden pond or water feature. If you have ever admired the bold leaves and vibrant blooms of a canna lily, you might have wondered if these sun-loving plants can survive with their roots submerged. The good news is that canna lilies are incredibly versatile and can indeed thrive in water, provided you follow a few simple steps to help them transition.

At Longfield Gardens, we enjoy helping gardeners find creative ways to use bulbs and perennials to enhance their outdoor spaces. While most people think of cannas as purely terrestrial plants for flower beds and borders, they are actually well-suited for the "marginal" areas of a pond where the water is shallow. Our Tall Cannas selection is a good place to start if you want bold foliage and dramatic height in a water garden.

In this article, we will explore which types of canna lilies work best in water and how to plant them for the best results. We will also cover essential care tips and how to manage these plants as the seasons change. Whether you have a large backyard pond or a small container water garden on your patio, canna lilies can be the star of the show.

Yes, You Can Grow Canna Lilies in Water

The short answer is a definitive yes. Canna lilies are among the few popular garden plants that can adapt to both traditional garden soil and aquatic environments. In nature, many species of canna are found growing in wetlands, marshes, and along the banks of rivers in tropical and subtropical regions. This evolutionary background means they are naturally equipped to handle "wet feet" better than most other summer-blooming bulbs, as explained in our All About Cannas guide.

When grown in water, cannas are typically treated as marginal plants. This means they grow best in shallow water, usually with about two to six inches of water covering the top of their root system or "crown." They are not true aquatic plants that live entirely submerged like seaweed, nor are they floating plants like water lilies. Instead, they sit at the edge of the water, with their roots anchored in soil or gravel while their stems and leaves reach toward the sun.

Growing cannas in water offers several benefits for the home gardener. Because they are heavy feeders, cannas are excellent at absorbing excess nutrients from pond water, which can help keep the water clearer and reduce algae growth. Their tall, dense growth also provides excellent cover for fish and other pond life. Most importantly, the constant access to moisture often leads to exceptionally large, healthy foliage and prolific blooming throughout the summer.

The Difference Between Land and Water Cannas

While almost all canna lilies appreciate consistent moisture, there are specific varieties known as "water cannas" that are particularly well-suited for aquatic life. These are often hybrids of Canna glauca, a species native to the wetlands of South America. Water cannas typically have narrower, more pointed leaves and a slightly more graceful, airy appearance than their chunky terrestrial cousins.

However, you do not necessarily need a specialized "water canna" to enjoy these plants in your pond. Many of the standard varieties we offer at Longfield Gardens, such as the famous Canna Tall Tropicanna or the dark-leaved Canna Tall Tropicanna Black, can adapt beautifully to life in a water garden. The key is in how you introduce them to the water.

The main difference between growing them on land versus in water is the way the roots handle oxygen. In a traditional garden bed, the soil must be well-draining so the roots can access air pockets. In a water garden, the plant must adapt to a lower-oxygen environment. This is why it is usually easier to start with a plant that has already begun to grow rather than dropping a dormant rhizome directly into deep water.

Key Takeaway: While specialized water canna hybrids exist, many standard garden varieties can thrive in shallow water if they are introduced properly once active growth has started.

How to Transition Cannas to a Water Garden

If you want to move a canna lily from your garden or a nursery pot into your pond, timing is the most important factor. Cannas are tropical plants that love heat. They will not be happy if they are placed in cold pond water in early spring. For more planting guidance, see our Garden Basics hub.

Wait until the water temperature in your pond consistently reaches at least 65°F to 70°F. In most parts of the US, this happens in late spring or early summer, well after the danger of frost has passed. Planting them too early in cold, stagnant water can cause the rhizome to rot before it has a chance to establish itself.

It is also much more successful to use a plant that already has several inches of green growth. If you have dormant rhizomes, plant them in a pot with standard potting soil first. Keep them in a warm, sunny spot and water them regularly until they are about 6 to 12 inches tall. Once the plant is established and the weather is warm, it is ready for its move to the water.

Steps for Transitioning:

• Start your canna rhizomes in pots with soil during early spring.
• Wait for the plant to reach at least 10 inches in height.
• Ensure the pond water has warmed to at least 65°F.
• Gradually move the pot into the shallow areas of the pond.

Best Practices for Planting Cannas in Ponds

When planting cannas for a water feature, you generally have two choices: planting them in a submerged container or planting them "bare root" in a gravel bog filter. Most home gardeners find the container method to be the easiest to manage.

Using Submerged Containers

To plant a canna in a container for your pond, choose a sturdy plastic pot that is at least 10 to 12 inches in diameter. Avoid using standard potting mixes that contain perlite or vermiculite, as these white bits will float out and create a mess in your pond. Instead, use a heavy garden soil or a specialized aquatic planting medium.

Fill the pot about two-thirds full with soil, place the canna inside, and fill in the rest of the soil around the roots. To keep the soil from washing away and to prevent curious fish from digging, top the pot with a one-inch layer of pea gravel or small river stones. Once potted, slowly lower the container into the pond. Position it on a "marginal shelf" so that the water level is only a few inches above the top of the pot.

The Bare Root Method

In some water garden setups, particularly those with a biological gravel filter (often called a "bog"), cannas can be planted directly into the gravel without any soil. In this environment, the plants act as a powerful filter, pulling nitrogen and phosphorus directly from the water through their roots. To do this, simply rinse all the soil off the roots of a growing canna and tuck the roots into the gravel so the plant stays upright. The flowing water will provide all the nutrients the plant needs.

What to Do Next:

• Choose a heavy plastic pot with no drainage holes or very small ones to keep soil contained.
• Use heavy clay-based soil rather than light, airy potting mixes.
• Top the soil with a layer of gravel to protect the pond's clarity.
• Place the pot in a sunny spot where it will receive at least 6 hours of light.
• Ensure the crown of the plant is no more than 6 inches below the water surface.

Choosing the Best Varieties for Water Planting

While many cannas can adapt to water, some are more popular than others for their striking visual impact and reliable performance in aquatic settings. When you browse our selection at Longfield Gardens, look for varieties that offer bold foliage, as the leaves are often just as decorative as the flowers.

Colorful Foliage Varieties

Varieties like Tropicanna are famous for their multicolored leaves featuring stripes of gold, red, and green. In a pond setting, these colors seem even more vibrant against the reflection of the water. Another excellent choice is Pretoria (also known as Striata), which has bright yellow and green variegated leaves that look like stained glass when the sun shines through them.

Dark Foliage Varieties

If you want to create a dramatic contrast in your water garden, consider a variety like Tropicanna Black. Its deep burgundy, almost chocolate-colored foliage provides a stunning backdrop for its bright orange blossoms. The dark leaves stand out beautifully against the greens and blues typically found in and around a pond.

Classic Water Hybrid Varieties

If you can find them, the "Longwood" hybrids are specifically bred for aquatic life. These include varieties like 'Endeavour' (red flowers), 'Ra' (bright yellow), and 'Erebus' (salmon pink). These plants are exceptionally vigorous in water and tend to have a slightly more refined habit that fits perfectly into a garden pond.

Key Takeaway: Choosing varieties with colorful or dark foliage ensures your water garden looks spectacular even when the plants are between bloom cycles.

Caring for Cannas in a Water Environment

Caring for cannas in water is remarkably simple because you never have to worry about watering them! However, there are a few maintenance tasks that will keep them looking their best and blooming all season long. If you want more background on selection and care, the All About Cannas article is a helpful companion.

Light and Temperature

Cannas are sun worshippers. For the best growth and the most flowers, your pond should be in a location that receives at least six to eight hours of direct sunlight every day. If they are in too much shade, the plants will become "leggy" and may fail to bloom. Additionally, remember that cannas stop growing when temperatures drop. They thrive in the heat of mid-summer and will put on their best show when the weather is sweltering.

Fertilizing in Water

Cannas are hungry plants. If you are growing them in a pot with soil, they will benefit from a regular boost of nutrients. You can use specialized aquatic fertilizer tabs that are pushed into the soil near the roots. These tabs are designed to release nutrients slowly without leaching into the water and causing algae blooms. If you are growing them bare-root in a bog filter, they will usually get plenty of nutrients from the fish waste and organic matter in the water.

Managing Growth

Cannas grow quickly in water. By mid-summer, a single rhizome can turn into a large, heavy clump. This can sometimes make the pots top-heavy, causing them to tip over in the wind. To prevent this, you can place a few heavy rocks inside the bottom of the pot before planting or use a wider, heavier container. If the plant becomes too large for its space, don't be afraid to trim back some of the outer stalks to maintain a pleasing shape.

Deadheading

To encourage the plant to keep producing new flowers, remove the faded blooms before they turn into seed pods. Simply cut the flower stalk back to the next side bud or leaf. This keeps the plant’s energy focused on creating more flowers rather than producing seeds.

Overwintering Water-Grown Canna Lilies

One of the most important things to remember is that canna lilies are not hardy in most of the United States. They are tender perennials, typically only surviving the winter in the ground in USDA zones 8 through 11. If you want a quick reference for your area, use our Hardiness Zone Map. When grown in a pond, they are even more vulnerable to cold because the water can quickly reach freezing temperatures.

As soon as the first frost hits and the foliage turns brown, it is time to move your cannas out of the water. Do not leave them in the pond over the winter, as the rhizomes will turn to mush and die in the cold, wet conditions. For details on seasonal fulfillment, visit our Shipping Information page.

Steps for Winter Storage:

1. Lift the pots out of the pond after the first frost has blackened the leaves.
2. Cut the stems back to about 4 to 6 inches above the soil line.
3. Remove the plant from the pot and gently wash away the pond soil or gravel.
4. Allow the rhizomes to dry in a shady, frost-free area for a few days.
5. Store the rhizomes in a box filled with slightly damp peat moss, sawdust, or vermiculite.
6. Keep the box in a cool, dark place (like a basement or crawl space) where the temperature stays between 40°F and 50°F.

Check on your stored rhizomes a couple of times during the winter. If they look shriveled, mist the packing material with a little water. If you see any soft or moldy spots, remove those pieces immediately to prevent the rot from spreading. In the spring, you can start the process all over again by potting them up and waiting for the pond water to warm.

Creating a Lush Water Garden Landscape

Cannas are excellent "thriller" plants in the world of water garden design. Their height and bold textures make them a natural focal point. To create a professional-looking water feature, try layering your plants by height.

Place your cannas at the back or center of the pond to provide height. In front of them, you can add mid-sized marginal plants like Pickerel Weed or Arrowhead. Finally, finish the look with low-growing or floating plants around the edges. This creates a "stadium seating" effect that allows you to see every plant clearly.

Because cannas come in so many foliage colors, you can use them to set the mood of your garden. For a hot, tropical look, pair orange-flowered cannas with red hibiscus and yellow water lilies. For a more serene, sophisticated look, use pink-flowered cannas with variegated foliage and white-flowering marginals. If you enjoy that kind of layered planting inspiration, the Garden Basics pages are full of design ideas.

Troubleshooting Common Issues

While cannas are generally very easy to grow in water, you might encounter a few minor hurdles. The most common "problem" is actually a sign of success: the plants grow so fast that they outgrow their pots or become too tall and tip over. If you want to learn more about Longfield’s growing standards, the About Us page explains our quality guarantee.

If your canna isn't blooming, the most likely cause is a lack of sunlight. Even "bright shade" is often not enough for a canna to produce flowers. Another possibility is that the water is too cold or the plant isn't getting enough nutrients. Ensure the pot is positioned in the sunniest spot in the pond and consider adding a fertilizer tab if growth seems slow.

You might also notice some leaf damage from slugs or snails, which love the moist environment of a pond. Usually, the plants grow fast enough that a little bit of nibbling won't hurt them. If the damage is severe, you can manually remove the pests or move the pot slightly further away from the pond's edge to make it harder for land-based slugs to reach the foliage.

Conclusion

Canna lilies are a fantastic addition to any water feature, offering a blend of tropical beauty and practical water-filtering benefits. By understanding that they prefer "wet feet" rather than being fully submerged and by waiting for the water to warm up before planting, you can enjoy these stunning plants all summer long. Their ability to adapt from garden beds to pond margins makes them one of the most versatile choices for the home gardener.

Whether you choose a classic water hybrid or a colorful variety like those we provide at Longfield Gardens, your pond will surely benefit from the height and vibrancy these plants provide. Gardening is all about experimenting and finding what brings you the most joy, and seeing a canna lily bloom in the middle of a pond is a truly rewarding experience.

• Wait for pond water to reach 65°F before planting.
• Use heavy soil and a gravel top-layer in submerged pots.
• Provide at least 6-8 hours of direct sunlight.
• Remove rhizomes from the water before the first hard freeze.

Growing canna lilies in water is a simple way to bring a touch of the tropics to your backyard. With their bold leaves and bright flowers, they turn any pond into a spectacular summer sanctuary.

We invite you to explore the different colors and textures available in our collection and start planning your own water garden oasis. For more tips on growing and caring for your favorite summer bulbs, visit our Garden Basics page and let us help you grow a garden you love.

FAQ

Do canna lilies need soil to grow in a pond?

While canna lilies can grow "bare root" in gravel filters or bogs where water is constantly circulating, they generally perform best for home gardeners when planted in a pot with heavy soil. The soil provides a steady supply of nutrients and helps anchor the plant so it doesn't tip over. If you choose the bare root method, the plant must be in a spot where it can pull nutrients directly from the pond water.

How deep can I submerge my canna lily?

Canna lilies are marginal plants, meaning they like shallow water. The ideal depth is usually two to six inches of water over the top of the pot or the plant's crown. If you submerge them too deeply, the stems may struggle to reach the surface, and the base of the plant could potentially rot. Using a "marginal shelf" in your pond is the best way to maintain the correct depth.

Can any variety of canna grow in water?

Most varieties of canna lilies can adapt to growing in water if they are transitioned correctly. While specific "water canna" hybrids like Canna glauca are naturally adapted to wetlands, popular garden varieties like Tropicanna and Wyoming also thrive in aquatic environments. The most important factor is making sure the plant has started growing in soil first and that the pond water is warm enough.

Will canna lilies survive the winter in my pond?

No, canna lilies will not survive the winter in a pond in most regions. They are tropical plants and the rhizomes will rot if they are left in cold, freezing water. Once the first frost hits, you should remove the plants from the pond, cut back the foliage, and store the rhizomes in a cool, dry place indoors until the following spring. Only gardeners in very warm climates (Zones 9-11) can potentially leave them in the water year-round.