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Can Canna Lilies Live In Water?

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Are you considering a pond for your landscaping or garden space? Wondering if this colorful plant would thrive in a pond? You're in luck because we've researched all about Cannas, and we've got the answer below!

Water gardens require plants that prefer humid and moist environments. Canna lilies thrive in this environment, making them perfect for aquatic gardens.

Technically almost all Canna lilies can adapt to being partially submerged in aquatic gardens or ponds. However, several varieties of Canna lilies are preferred and considered an excellent choice to grow in water.

The varieties of Canna that are considered best to grow in an aquatic garden or ponds are:

  • Canna Glauca
  • Canna Cleopatra
  • Hardy Water Canna
  • Canna Tropicanna

Now that we've established the very best varieties of Canna that can live and thrive in the water, we will discuss exactly how to plant and care for them in water environments. We will also answer some commonly asked questions about Cannas.

Orange canna lillies growing in a pond, Can Canna Lilies Live In Water?

How Do You Grow Canna Lilies In Water?

Growing Cannas in an aquatic garden is a relatively simple process. The first step is to purchase your Canna bulbs. Then follow the steps below.

  1. Procure an aquatic planter with enough space to give your Cannas room to grow. You will want to shoot for a pot at least 18 inches in diameter. You will want the plants spaced 1-4 feet apart.
  2. Get either clay-based gardening soil or aquatic compost.
  3. Place a thin layer of clay or compost on the bottom of the aquatic planter. Place your bulbs on top of this and thoroughly cover with clay or compost.
  4. If you have fish, place a layer of gravel on top to prevent them from disturbing the soil.
  5. Once your planter is ready, find a good spot in your pond to place it, preferably in full sun and near the edge of the pond or garden, not in the middle.
  6. Place the pot in the water submerging only the stems, leaving the leaves out. If you're in a colder climate, you will want to bring the pots in at first frost and keep them damp while storing.

Vertical view of canna lily in the pond of amphitheater in Untermyer park

Here is a helpful visual tutorial on how to get your Cannas growing in a water garden.

What Are The Best Varieties Of Canna for Aquatic Gardens?

As stated above, there are four varieties of Canna lilies that are considered the best for aquatic gardens or ponds. We will touch briefly on each variety.

A little-known fact about these beautiful lilies is they can be used as a water filter. They can remove pollutants from standing water, including toxic heavy metals, nitrogen, phosphorus, and radioactive nuclides.

Canna Tropicanna

Canna Tropicanna plant leaf

Canna Tropicanna is considered ideal for ponds or aquatic gardens. They are known for their distinct foliage. They typically have bright orange blooms.

While their blooms are beautiful, what makes the Canna Tropicanna stand out are their leaves. Their leaves are a deep burgundy displaying bright, colorful stripes throughout. They grow best in USDA zones 7-11.

Canna Cleopatra

Canna Cleopatra Lily Flower with a soft background

Canna Cleopatra can display many different combinations of flowers. Canna Cleopatra is considered an unstable variety, so gardeners don't know what they'll get until the plant blooms!

The flowers can be solid yellow, yellow with red spots, pure red, or any combination of the two! The leaves can either be pure green or occasionally a chocolate brown. They grow best in USDA zones 8-11.

Canna Glauca

Canna glauca flower in the afternoon sun

Canna Glauca is also known as Water Canna. It is the perfect specimen to be grown in an aquatic garden or a pond. This is mainly because its native habitat is marshes, swamps, ponds, and wet ditches.

Canna Glauca produces gladiolus-like blooms that are typically soft yellow but can be found in red, pink, or orange. They grow best in USDA zones 9-11.

Hardy Water Canna

This variety of Canna is also known as Powdery Alligator-Flag. This is due to its native habitat being the wetlands of the southeastern United States and the water-resistant, white powdery coating covering the entire plant.

Hardy Water Canna has blue-green foliage and purple flowers. It is fast-growing and grows best in USDA zones 7-10. It requires very little attention or care but does grow best when only partially submerged.

Tips For Growing Cannas

A few tips for growing Canna successfully.

  • Pick a spot with full sunlight. Canna thrives in full sun. Not only does this create and encourage better foliage, but it also increases bloom production.
  • Wait to plant outdoors until all threat of frost has passed. They can easily be started indoors and transferred outdoors during the warm months.
  • They like fertilizer that is higher in phosphate for continual blooms.
  • Deadhead the blooms when they die back.

How To Overwinter Cannas From A Pond?

If growing in zones eight or higher, you can leave the Cannas in the aquatic garden or pond. You only need to make sure the plant is submerged in the water enough to protect the roots from any frost damage.

The Cannas can be stored in their pots. It is best to cut the foliage down to the soil level. Move the entire container indoors or where it will not get below 40 and keep the soil damp.

You can store the rhizomes in a cool basement, garage, or cellar. If opting for any of these, you will want to keep them in darkness. They can also be overwintered indoors in an aquarium with full-spectrum lighting.

It's important to note that rhizomes can rot in poorly drained soil when stored. They can also be stored in a dry medium such as peat over winter.

Can You Leave Canna Lilies In The Ground?

Cannas planted in zones eight and warmer can be left in the ground during winter. These winters are not harsh enough to require removal.

Zones 6 and colder will require removal from the ground. You will want to remove them from the ground after the first frost.

To overwinter Canna in zones six and colder, you will want to cut back to about 2 inches from the soil. Remove the Canna either individually or in one large clump from the ground.

Place in a pot with compost. Store in a cool, dry, dark area protected from frost. Here is a helpful video on removing Canna from the ground.

If you're growing in Zone 7, the rhizome can be left in the ground with added protection. Cut back the stalk to just a few inches above the soil and then place either leaf mulch or a straw layer over the top of the plants. Note that if removed from the ground, there is the added benefit of faster growth in spring.

Are Cannas Poisonous To Fish?

Koi carp fishes in the pond of Phuket botanical carden

There is no evidence to point to Cannas being poisonous or toxic to fish. Evidence shows no parts of the plant are toxic to humans, cats, or dogs, so it is safe to say it is also non-toxic to fish.

Do You Fertilize Cannas In Water?

Monthly fertilizer designed for use in aquatic gardens is beneficial. Never use traditional fertilizer in an aquatic garden.

You will want to follow the manufacturers' directions for use. You can find aquatic fertilizer in liquid, substrate, and tablet forms.

Do Canna Lilies Like Wet Soil?

All varieties prefer moist soil for Canna Lilies planted in the ground, though they will tolerate well-draining soil. 

If Cannas are not in an environment with moist soil, they will require weekly irrigation. Keeping the first 6 to 8 inches of soil moist is a must.

Are Cannas Fast Growing?

Cannas can take some time to sprout from their bulbs. However, once sprouting does begin, they tend to grow at a rapid pace, so long as they favor their growing conditions.

What Month Do You Plant Cannas?

Nailing down a specific month is nearly impossible and depends on where you live. However, you will want to plant your Cannas in the early summer or late spring months.

Most gardeners abide by the rule of thumb once all the danger of frost has passed. Canna lilies can also be started indoors months before moving outdoors.

In Summary

Canna lilies are an excellent addition to any aquatic garden. They are easy to care for, grow quickly, and provide a burst of color to any pond or aquatic garden. We hope we've provided you with enough information to feel confident growing Canna lilies in a water environment.

If you've enjoyed this article, consider these for further reading:

How To Build A Pond In Sandy Soil

How Much Compost To Add To Clay Soil