Can You Grow Canna Lilies in Water?

Table of Contents

1. Introduction
2. Understanding the Aquatic Nature of Cannas
3. Types of Canna Lilies for Water Gardening
4. How to Grow Cannas in Water: A Step-by-Step Guide
5. Best Practices for Successful Growth
6. Container Gardening: Cannas in "Water Pots"
7. Care and Maintenance Throughout the Season
8. Overwintering Aquatic Cannas
9. Troubleshooting Common Issues
10. Conclusion
11. FAQ

Introduction

There is something truly magical about the lush, oversized leaves and vibrant blooms of canna lilies. These plants bring an immediate tropical flair to any setting, making your backyard feel like a private island getaway. While most gardeners think of them as traditional border plants, many are surprised to learn how much these sun-lovers actually enjoy having "wet feet."

At Longfield Gardens, we want to help you explore the full potential of these versatile plants. Whether you have a backyard pond, a small water feature, or just a decorative pot on your patio, cannas can be a stunning addition to your aquatic landscape. We focus on providing high-quality rhizomes that give you a head start on a beautiful, thriving garden. If you want to browse the most relevant selections first, start with our Tall Cannas collection.

This guide will explain exactly how you can grow canna lilies in water, which varieties work best, and the simple steps you can take to ensure they bloom all summer long. If you have ever wondered if your water feature could use a splash of bold color, you are in the right place. Growing cannas in water is a rewarding way to add height and drama to your landscape.

Understanding the Aquatic Nature of Cannas

To understand why canna lilies do so well in water, it helps to look at where they come from. Many species of canna are native to the wetlands and marshy areas of Central and South America. In their natural habitat, they often grow along the edges of rivers and ponds where the soil stays consistently moist or even submerged.

Because of this ancestry, cannas have a unique root system designed to handle low-oxygen environments that would cause other plants to rot. The thick, fleshy roots, known as rhizomes, act as storage tanks for energy. When they are placed in a water-rich environment, they can focus all that energy on producing massive leaves and bright flowers. If you want a deeper look at that underground structure, see our guide on canna root systems.

It is important to remember that while cannas love water, they also love warmth. In the garden, they thrive when the sun is high and the temperatures are consistent. When you move them into a water feature, these two needs—moisture and heat—come together to create rapid growth. This makes them an excellent choice for gardeners who want a high-impact plant that fills in quickly during the summer months.

Types of Canna Lilies for Water Gardening

When you are deciding which cannas to put in your pond or water feature, you generally have two choices. You can look for specific "water canna" hybrids, or you can use standard terrestrial cannas that are adapted to wet conditions.

Water Canna Hybrids

There is a specific group of cannas often called Longwood hybrids. These were specifically bred to live in shallow water. These varieties often have a more upright, slender growth habit and blue-green foliage that looks stunning against the water's surface. Common varieties in this group include 'Endeavour' (red), 'Erebus' (salmon pink), and 'Ra' (bright yellow). These are the gold standard for pond planting because they are naturally resistant to the stresses of being submerged.

Terrestrial Cannas

Interestingly, many of the common canna lilies we grow in garden beds also adapt very well to water. Bold varieties with variegated foliage, like Canna Tall Pretoria or Canna Tall Tropicanna Black, are frequent favorites for water features. The key difference is that these varieties often grow much larger and more aggressively when they have access to constant moisture. If you use a standard variety, be prepared for it to reach its maximum height and perhaps even exceed it.

Key Takeaway: Most cannas can adapt to water, but specific aquatic hybrids like the Longwood series are the most reliable for permanent placement in ponds.

How to Grow Cannas in Water: A Step-by-Step Guide

Growing cannas in water is not as simple as tossing a rhizome into a pond. To get the best results, you should follow a few easy steps that help the plant transition from a dry state to an aquatic one.

Step 1: Start with Healthy Rhizomes

Success begins with high-quality starting material. Look for rhizomes that feel firm and heavy for their size. Avoid anything that feels light, shriveled, or soft. At Longfield Gardens, we ensure our rhizomes are stored in ideal conditions so they arrive at your door ready to grow. Our Shipping Information page explains how orders are timed to your hardiness zone.

Step 2: Pre-Sprouting in Soil

This is the most important step for aquatic canna gardening. You should never put a dormant, dry rhizome directly into a pond. Without active roots and leaves, a dormant rhizome is likely to rot in cold, still water.

Instead, plant your rhizomes in a pot with standard potting soil in early spring. Keep the pot in a warm, sunny spot and water it regularly. Wait until the plant has grown at least 6 to 12 inches tall and has several healthy leaves before moving it to the water. This ensures the plant has the energy it needs to thrive in its new environment. For a broader look at canna growth timing, see our guide to canna heights.

Step 3: Transitioning to the Water

Once your canna is actively growing, it is time to move it to its permanent water home. You should repot the plant into a container that does not have drainage holes, or use a mesh aquatic basket lined with burlap.

Use a heavy, clay-based garden soil rather than a light potting mix. Light mixes often contain perlite or vermiculite, which will float out of the pot and create a mess in your pond. Pack the soil firmly around the rhizome and top the pot with a layer of heavy gravel or river stones. This layer of stones keeps the soil in place and prevents your fish from digging in the dirt. For more planting basics, our deep planting guide is a helpful reference.

Step 4: Placing in Your Pond

Slowly lower the pot into your water feature. The goal is to have the top of the pot sitting just below the surface of the water. Ideally, there should be no more than 2 to 6 inches of water covering the soil. This depth allows the "feet" of the plant to stay wet while the crown and foliage remain above the water line to breathe and soak up the sun.

Best Practices for Successful Growth

To keep your cannas looking their best throughout the summer, you need to pay attention to a few environmental factors. While they are low-maintenance once established, getting the environment right makes a big difference.

Lighting and Location

Cannas are sun-worshippers. They need at least 6 to 8 hours of direct sunlight every day to produce their best flowers. If they are in too much shade, the plants will become "leggy," meaning they grow tall and thin as they reach for the light, and they may fail to bloom. When placing them in a pond, choose the sunniest side where they won't be shaded by trees or nearby structures.

Water Temperature

Cannas love heat. They will not start growing vigorously until the water temperature reaches at least 65°F to 70°F. If you put them in a pond too early in the spring while the water is still chilly, they may sit dormant or grow very slowly. Patience is a virtue here; wait for the weather to warm up consistently before moving your pots into the water.

Fertilizing for Blooms

Cannas are heavy feeders. Because they grow so fast and produce such large leaves, they need a lot of nutrients. In a garden bed, you would use compost or granular fertilizer. In a pond, you can use specially designed aquatic fertilizer tabs. Simply push a tab into the soil of the pot once a month during the growing season. This provides a steady supply of nutrients without encouraging algae growth in the surrounding water. For spacing and vigor tips that also help with strong growth, see our spacing guide for canna bulbs.

What to Do Next:

• Check your water temperature with a simple pond thermometer.
• Identify the sunniest spot in your water feature.
• Purchase heavy garden soil and river rocks for potting.
• Order your favorite canna varieties from a trusted source.

Container Gardening: Cannas in "Water Pots"

You don't need a full-sized pond to enjoy the look of aquatic cannas. One of the most popular ways to grow them is in "water-in-water" containers. This is a great solution for patios, balconies, or small entryways.

To do this, find a decorative ceramic or plastic pot that does not have a drainage hole. This will be your "outer pot." Then, plant your canna in a smaller, plain plastic pot with drainage holes. Place the smaller pot inside the larger one. Fill the larger pot with water until it reaches the rim of the inner pot.

This method creates a self-watering system that cannas absolutely love. You won't have to worry about the soil drying out, even on the hottest summer days. Just top off the water every few days to keep it fresh. This setup also makes it very easy to move the plants if you want to change your patio layout.

Care and Maintenance Throughout the Season

Cannas are known for their rapid growth. In the right conditions, a single rhizome can turn into a massive clump in just one season. While this is great for creating a "jungle" look, it does require a little bit of maintenance.

Managing Rapid Growth

If your canna is growing in a small pond, it can eventually become top-heavy. Because they grow so tall, wind can sometimes catch the large leaves and tip the pot over. To prevent this, ensure you are using a heavy pot and plenty of stones at the base. If the plant becomes too large for its container, you may need to divide it mid-season or move it to a larger, heavier pot.

Deadheading and Pruning

To keep the flowers coming all summer, you should "deadhead" the plants. This simply means cutting off the spent flower stalks once they finish blooming. Cut the stalk down to where it meets the next set of leaves. This encourages the plant to put its energy into new flower spikes rather than producing seeds.

You should also remove any leaves that turn yellow or brown. In a water environment, old leaves can fall into the water and decay, which can affect the water quality of a small pond. Keeping the plant tidy helps the overall health of your aquatic ecosystem.

Overwintering Aquatic Cannas

Cannas are tender perennials. This means they cannot survive freezing temperatures. If you live in a cold climate (USDA zones 7 and colder), you will need to bring your cannas inside for the winter.

Wait until the first light frost hits in the fall. The frost will turn the foliage black, which is a signal that the plant is going dormant. At this point, lift the pot out of the water and cut the stalks down to about 2 or 3 inches above the soil.

You have two options for storage:

1. The Pot Method: Keep the entire pot in a cool, dark, frost-free place like a basement or crawlspace. Don't let the soil get bone-dry, but don't keep it soaking wet either. A little bit of moisture once a month is usually enough.
2. The Bare-Root Method: Remove the rhizomes from the pot, wash off the soil, and let them dry for a few days. Store them in a box filled with slightly damp peat moss or sawdust.

When spring returns and the danger of frost has passed, you can start the process all over again by pre-sprouting the rhizomes indoors.

Troubleshooting Common Issues

While cannas are generally robust, there are a few things to keep an eye on when growing them in water. We believe in leading with the right approach to prevent problems before they start.

Lack of Blooms

If your canna is growing plenty of leaves but no flowers, it is usually due to one of two things: light or food. Ensure the plant is getting at least 6 hours of full sun. If it is, then it likely needs more fertilizer. Remember that cannas in water are isolated from the nutrients in the ground, so they rely entirely on the fertilizer tabs you provide.

Pests

Cannas can occasionally attract "canna leaf rollers," which are small caterpillars that stitch the leaves together before they unfurl. The best approach is to keep an eye on new growth. If you see leaves that are stuck together or have small holes, you can manually remove the pests. For a water-safe solution, check with your local extension service for recommendations that won't harm fish or other aquatic life.

Yellowing Leaves

If the leaves are turning yellow early in the season, check the water temperature. If the water is too cold, the plant cannot absorb nutrients properly. If the weather is warm and the leaves are still yellow, the plant may be hungry. Increasing your fertilizer schedule often solves the problem.

Conclusion

Growing canna lilies in water is one of the easiest ways to bring a bold, tropical aesthetic to your home landscape. By giving these plants the "wet feet" and "hot heads" they crave, you can enjoy some of the most dramatic growth in the garden world. Whether you choose a dedicated water hybrid or a colorful terrestrial variety, the results are sure to be impressive.

At Longfield Gardens, we take pride in helping you find the right plants for your unique space. Our rhizomes are backed by a 100% quality guarantee, ensuring they arrive in prime condition and are true to their variety. If you encounter any issues during your first growing season, our team is here to support you with replacements or advice.

Ready to start your aquatic garden? Here is your quick checklist for success:

• Choose a sunny spot with at least 6 hours of light.
• Pre-sprout your rhizomes in soil before moving them to water.
• Use heavy garden soil and stones to keep pots stable.
• Fertilize regularly with aquatic tabs for the best blooms.

Growing cannas in water is a rewarding project that transforms a simple pond into a lush, flowering oasis. With just a little bit of sun and consistent warmth, these plants will provide a stunning focal point all season long.

FAQ

Can I grow any variety of canna lily in water?

While almost all canna lilies enjoy moist soil, the "water canna" hybrids (such as the Longwood series) are the best for being submerged. Standard terrestrial varieties can also grow in water, but they must be pre-sprouted in soil first and should only have a few inches of water over their roots.

How deep should I submerge the canna pot?

Ideally, the pot should be submerged so that there are 2 to 6 inches of water above the soil line. You want the roots to be wet, but the main crown of the plant and the foliage should be above the water. If the water is too deep, the plant may struggle to get enough oxygen.

Do canna lilies in water need a lot of fertilizer?

Yes, cannas are very hungry plants. Because they are confined to a pot in the water, they cannot reach out into the ground for nutrients. Use aquatic fertilizer tablets pushed into the soil once a month during the peak growing season to ensure they have enough energy to bloom.

Will canna lilies survive the winter in a pond?

In USDA zones 8 to 11, cannas can often stay in the pond year-round, though they will go dormant in the winter. In zones 7 and colder, the rhizomes will freeze and rot if left outside. You must lift the pots and store them in a frost-free area until spring.