Can Canna Lilies Grow in Water? A Guide to Aquatic Cannas

Table of Contents

1. Introduction
2. The Versatility of Canna Lilies: From Borders to Water Gardens
3. Choosing the Right Canna for Your Water Feature
4. How to Grow Canna Lilies in Water: A Step-by-Step Guide
5. Caring for Aquatic Cannas Throughout the Season
6. Why Grow Cannas in Water? (The Benefits)
7. Overwintering Cannas Grown in Water
8. Simple Troubleshooting for Water-Grown Cannas
9. Conclusion
10. FAQ

Introduction

Few plants bring as much tropical flair and architectural drama to the landscape as the canna lily. With their oversized, paddle-shaped leaves and vibrant, orchid-like blooms, they are a favorite for adding height and color to summer gardens. Many gardeners are surprised to learn that these sun-loving beauties are not just limited to garden beds and patio pots. If you have ever wondered, "Can canna lilies grow in water?" the answer is a resounding yes. In fact, certain varieties of cannas thrive with their "feet" submerged, making them a spectacular choice for ponds, water features, and boggy areas.

At Longfield Gardens, we enjoy helping home gardeners discover new ways to use versatile plants like cannas to create a lush, resort-like atmosphere at home. Whether you have a sprawling backyard pond or a simple decorative water basin on your deck, cannas can provide the vertical interest and bold texture you need. This guide will walk you through everything you need to know about growing canna lilies in water, from selecting the right varieties to the simple steps for planting and maintenance. By understanding a few basic principles of aquatic gardening, you can enjoy these stunning flowers in a whole new environment.

The Versatility of Canna Lilies: From Borders to Water Gardens

Cannas are known for being tough, adaptable plants. While most people grow them in traditional garden soil, they are naturally suited to moist environments. In their native habitats across tropical and subtropical regions of the Americas, many canna species are found growing along the edges of marshes, riverbanks, and wetlands. This natural history is what makes them such excellent candidates for water gardening.

When you grow cannas in water, you are tapping into their inherent love for moisture and heat. Unlike many other bulbs and rhizomes that might struggle with rot in overly wet conditions, the canna lily has developed a specialized structure that allows it to handle saturated soil. This makes them a "problem solver" plant for areas of the yard where the soil stays consistently wet, or as a centerpiece in a managed water feature.

Growing cannas in water also offers a unique aesthetic advantage. The reflection of their bright orange, red, or yellow flowers on the surface of a pond creates a stunning visual effect. Furthermore, the height of cannas—ranging from three to six feet or more—provides a necessary vertical element that many low-growing aquatic plants lack.

Choosing the Right Canna for Your Water Feature

While many cannas can tolerate damp soil, not all are equally suited to living in standing water. If you want the best results, it helps to distinguish between "garden cannas" and "water cannas."

Water Cannas vs. Garden Cannas

Water cannas (often derived from the species Canna glauca) are specifically bred or selected for their ability to grow in aquatic environments. These varieties tend to have more slender leaves and a more upright, graceful habit. They are exceptionally efficient at filtering nutrients from the water, which can actually help keep your pond cleaner.

Standard garden cannas, which are the most common varieties found in home landscapes, can often be adapted to grow in water, but they require a bit more care during the transition. If you take a garden canna that has been growing in dry soil and move it directly into a deep pond, it may experience some stress. However, if you start them in a pot and gradually move them into the water as they grow, many will flourish.

Recommended Varieties for Water

When looking for cannas to grow in your water feature, keep an eye out for these proven performers:

• Erebus: This is one of the most popular water cannas. It features gorgeous salmon-pink flowers and attractive blue-green foliage. It typically reaches about 3 to 4 feet in height.
• Endeavour: A stunning variety with bright, raspberry-red flowers. It is a vigorous grower and can reach 5 to 6 feet, making it a great choice for the back of a pond.
• Ra: Named after the Egyptian sun god, this variety produces brilliant lemon-yellow flowers. It has a very upright habit and can grow to 5 or 6 feet.
• Bengal Tiger (also known as 'Pretoria'): While often grown in soil, this variety is a water-gardening favorite because of its spectacular variegated leaves (green and yellow stripes) and bright orange flowers. It adds a massive punch of color even when not in bloom.

Key Takeaway: For the most reliable results in a pond or water feature, look for Canna glauca hybrids like 'Erebus' or 'Ra'. These are naturally adapted to aquatic life and will thrive with minimal fuss.

How to Grow Canna Lilies in Water: A Step-by-Step Guide

Growing cannas in water is remarkably straightforward. You aren't just tossing a rhizome into a lake; instead, you are planting it in a container and then submerging that container into the water. This method, often called "potted aquatic planting," gives you control over the plant's position and makes it much easier to manage.

Preparing Your Containers

To grow cannas in water, you need a sturdy plastic pot. A 5-gallon bucket or a large nursery pot (at least 10–12 inches in diameter) works well for larger varieties. If you are placing the plant in a formal pond, you might prefer "aquatic baskets," which are mesh pots designed to allow water to flow through the root zone while keeping the soil contained.

One common mistake is using standard potting mix. Most potting soils are designed to be lightweight and contain perlite or vermiculite, which will float out of the pot and create a mess in your pond. Instead, use a heavy, clay-based garden soil or a specialized aquatic planting medium. The weight of the clay helps keep the pot anchored at the bottom of the water feature.

Potting Up the Rhizomes

1. Fill the Pot: Fill your container about two-thirds full with your heavy soil or aquatic mix.
2. Position the Rhizome: Lay the canna rhizome horizontally on the soil surface. If there are visible "eyes" or growing tips, make sure they are pointing upward.
3. Cover with Soil: Add more soil until the rhizome is covered by 1 to 2 inches.
4. Add a Topping: To prevent the soil from washing away and to keep curious fish from digging, add a 1-inch layer of pea gravel or small river stones over the top of the soil.
5. Water In: Before placing the pot in your pond, water it thoroughly on dry land. This settles the soil and prevents air bubbles from lifting the plant once it’s submerged.

Placing Cannas in Your Pond or Water Feature

The most important rule for aquatic cannas is the depth of the water. While they love "wet feet," they do not want to be buried deep underwater.

When you first place your potted canna in the water, the water level should be just an inch or two above the soil surface (the "crown" of the plant). As the plant grows and establishes a strong root system, you can move it deeper. Most established water cannas do best when the water is between 2 and 6 inches above the top of the pot.

If your pond is deeper than 6 inches, you can use bricks or overturned pots as "pedestals" to raise the canna pot to the correct height. This ensures the plant gets plenty of oxygen and sunlight while keeping its roots in the refreshing water.

What to Do Next

• Select a heavy, non-floating soil for your aquatic pots.
• Place a layer of gravel on top of the soil to keep it in place.
• Start the pot at a shallow depth (1–2 inches of water over the soil).
• Use bricks or blocks to adjust the height in deeper ponds.

Caring for Aquatic Cannas Throughout the Season

Once your canna lilies are settled in their watery home, they are relatively low-maintenance. However, because they are growing in a confined space with a limited amount of soil, they do have a few specific needs to stay healthy and productive.

Light and Temperature Requirements

Canna lilies are sun worshippers. To produce those iconic, brilliant flowers, they need at least 6 to 8 hours of direct sunlight every day. If they are grown in too much shade, the plants may become "leggy" (tall and weak) and may fail to bloom.

Temperature also plays a big role. Cannas love the heat. They generally won't start growing vigorously until the water and air temperatures consistently stay above 60°F. If you live in a cooler climate, wait until the late spring or early summer to move your cannas into the water. The warmer the water gets, the faster they will grow.

Feeding Your Water Cannas

Cannas are "heavy feeders," meaning they require a lot of nutrients to fuel their rapid growth and large flowers. In a traditional garden, you might use granular fertilizer. In a pond, you need to be more careful.

The best way to feed aquatic cannas is with aquatic fertilizer tablets or spikes. These are designed to be pushed deep into the soil of the pot. They release nutrients slowly over several weeks without leaching into the water and causing algae blooms. Follow the package instructions, but generally, one or two tablets every month during the growing season will keep your cannas vibrant.

Maintenance and Deadheading

To keep your water garden looking its best, remove spent flowers regularly. This process, called deadheading, encourages the plant to put its energy into producing new blooms rather than setting seeds. When a flower spike has finished blooming, simply cut the stalk back to the next side shoot where a new bud is forming.

You should also remove any yellowing or tattered leaves. Because canna leaves are so large, they can occasionally catch the wind and tear. Trimming these off keeps the plant looking tidy and prevents decaying organic matter from falling into your pond water.

Key Takeaway: High light, warm water, and regular feeding with aquatic fertilizer tabs are the "secret" to lush, blooming water cannas.

Why Grow Cannas in Water? (The Benefits)

Beyond their sheer beauty, there are several practical reasons to include cannas in your aquatic setup.

1. Natural Filtration: Cannas are excellent at absorbing excess nutrients like nitrates and phosphates from pond water. By competing with algae for these nutrients, cannas can help maintain clearer water and a healthier ecosystem for fish.
2. Wildlife Habitat: The tall stalks and broad leaves provide shade and hiding spots for pond life, such as frogs and dragonflies. Pollinators like bees and hummingbirds are also naturally drawn to the bright blooms.
3. Versatility in Design: Cannas allow you to add height to a water feature that might otherwise feel "flat." They can be used as a living privacy screen or a focal point in the center of a circular pond.
4. No Watering Chores: One of the best perks of growing cannas in water is that you never have to worry about them drying out! While your garden beds might struggle during a mid-summer heatwave, your water cannas will be perfectly hydrated and happy.

Overwintering Cannas Grown in Water

Canna lilies are tender perennials, meaning they cannot survive freezing temperatures. In USDA zones 7 and colder, you will need to take action to save your plants for next year.

When the first light frost hits and the foliage begins to turn brown, it is time to pull the pots out of the water. Cut the stalks down to about 4 or 6 inches above the soil. At this point, you have two options:

1. The "Wet" Method: If you have a frost-free basement or a heated greenhouse, you can keep the entire pot as-is. Keep the soil slightly moist (but not submerged in water) throughout the winter.
2. The "Dry" Method: Remove the rhizomes from the pot, wash off the soil, and let them dry for a day or two in a shaded spot. Pack them in a box with slightly damp peat moss or sawdust and store them in a cool (40–50°F), dark place.

When spring returns and the danger of frost has passed, you can repot the rhizomes and start the process all over again. We recommend dividing the rhizomes every year or two to prevent them from becoming too crowded in their pots.

For help choosing plants that match your climate, use the Hardiness Zone Map.

Simple Troubleshooting for Water-Grown Cannas

While growing cannas in water is generally very successful, you may occasionally run into a few minor hurdles. Most can be solved with a simple adjustment to the plant's environment.

• Yellow Leaves: If the leaves are turning yellow but the veins remain green, the plant might be lacking iron or other micronutrients. This is common in aquatic environments. Ensure you are using fertilizer tabs specifically formulated for pond plants.
• No Blooms: If your canna is growing plenty of leaves but no flowers, it likely needs more sun. Move the pot to the sunniest part of your pond. If sun isn't the issue, the plant may need more fertilizer.
• Torn Leaves: Canna leaves are essentially giant sails. In very windy locations, they can shred. If possible, move the pot to a more sheltered corner of the pond or use lower-growing "dwarf" varieties that are less susceptible to wind damage.
• Algae in the Pot: If the soil surface in the pot is growing a lot of green algae, make sure you have a thick enough layer of gravel on top. You can also add more floating plants (like water lilies) to the pond to provide shade and reduce the light reaching the canna's pot.

If you want a broader refresher on summer-blooming bulbs, the Learn section is a useful place to start.

Conclusion

Growing canna lilies in water is a rewarding way to elevate your gardening game and bring a touch of the tropics to your backyard. By choosing water-tolerant varieties like 'Erebus' or 'Endeavour' and providing them with plenty of sun and nutrients, you can create a stunning aquatic display that lasts all summer long. Remember to keep the pots at a shallow depth and move them indoors when the weather turns cold.

At Longfield Gardens, we believe that gardening should be a source of joy and creative expression. Experimenting with cannas in a pond or water feature is a simple, effective way to transform your outdoor space. Whether you are a seasoned pond enthusiast or a beginner looking for a "wow" factor, the canna lily is a reliable and beautiful partner for your water gardening adventures.

• Choose Wisely: Use Canna glauca hybrids for the best aquatic performance.
• Pot it Right: Use heavy clay soil and a layer of gravel to keep the plant anchored.
• Follow the Sun: Ensure your water feature gets at least 6 hours of direct sunlight.
• Feed Regularly: Use aquatic-safe fertilizer tabs to keep blooms coming all season.

"A well-placed canna lily in a water feature acts as a living sculpture, blending the elegance of aquatic life with the boldness of tropical foliage."

Ready to start your own tropical oasis? Visit us at Longfield Gardens to explore our selection of Tall Cannas, Medium Cannas, and the Canna Assorted Collection for more options that can help your garden shine.

You can also review Shipping Information before you place an order, and learn more About Us if you'd like to know more about Longfield Gardens.

FAQ

Can I grow any type of canna lily in my pond?

While most canna lilies can tolerate very wet soil for short periods, the "water cannas" (hybrids of Canna glauca) are the most successful for long-term growth in standing water. Common garden cannas can often adapt if they are transitioned slowly and kept at a shallow depth, but water-specific varieties are much more reliable for beginners. If you want a ready-made shopping shortcut, start with Canna Tall Pretoria or Canna Tall Tropicanna.

How deep should I submerge my canna lily pot?

The water level should typically be 2 to 6 inches above the top of the pot. When you first move a canna into the water, start at the shallower end (1–2 inches) and gradually lower it as the plant grows and matures. Avoid submerging the plant so deeply that the emerging foliage is completely underwater. For a darker foliage choice, Canna Tall Tropicanna Black is a strong option.

Do I need special soil for aquatic cannas?

Yes, it is important to avoid standard potting mixes that contain perlite or peat, as these will float and cloud the water. Use a heavy, clay-based garden soil or a specific aquatic planting medium. Topping the soil with an inch of pea gravel or small stones will help keep the soil in the pot and protect it from fish or water movement.

Will aquatic cannas attract mosquitoes?

Canna lilies themselves do not attract mosquitoes, but standing water can be a breeding ground for them. If you grow cannas in a pond with moving water (like a waterfall or fountain) or keep fish that eat larvae, mosquitoes won't be an issue. For small, still-water basins, you can use "mosquito dunks" containing BTI, which is a natural bacteria that is safe for plants, pets, and wildlife but prevents mosquito larvae from developing.