Koi ponds are beautiful backyard features that allow you to raise colorful koi fish. However the ideal koi pond contains more than just fish – aquatic plants play an integral role in maintaining water quality and providing shade, shelter and ambience.
When selecting plants for a koi pond, it’s crucial to choose species that will thrive in your climate and pond conditions. Water lilies, lotuses, and marginal plants like iris and cattails are excellent choices. Floating plants like water hyacinth and water lettuce help control algae growth and provide cover. Oxygenating plants keep the water healthy for your fish.
Here are the top 10 best plants to include in your koi pond
1. Water Lily
Water lilies are classic pond plants that are loved for their pretty flowers and leaves that float on the water. The flowers come in shades of white, pink, yellow, and red. They give koi shade and a place to live, and they also help the water get rid of extra nutrients. Tropical day bloomers that open in the morning and close at night are a popular type of water lily. Hardy water lilies can withstand colder climates.
2. Lotus
Lotus (Nelumbo nucifera) has big, round leaves that can be up to 2 feet wide and look like lily pads. They float gracefully on the pond’s surface. From the middle of summer to the beginning of fall, lotuses bloom huge, fragrant flowers in shades of pink, yellow, red, and white. Lotus help shade the water and control algae. Their leaves, flowers, roots, and seeds are edible.
3. Water Hyacinth
Known for their lush green leaves and stunning purple flowers, water hyacinths (Eichhornia crassipes) float freely on the water. They help absorb nutrients, provide shade, and oxygenate the water. However, water hyacinths reproduce rapidly so you’ll need to thin them regularly.
4. Water Lettuce
Water lettuce (Pistia stratiotes) forms a thick, floating mat of soft green leaves that resemble miniature heads of lettuce. They help filter excess nutrients, control algae growth, and regulate water temperature. Water lettuce spreads readily in warm weather and may need thinning.
5. Duckweed
Duckweed (Lemna minor) is a tiny floating plant that resembles a green dot or leaf, hence its nickname “pond snow.” It multiples rapidly to form a dense floating mat. Duckweed shades and cools the water while absorbing dissolved nutrients. It’s a food source for koi and waterfowl.
6. Water Iris
Native iris plants, like the blue flag iris (Iris versicolor), do well in wet soil near koi ponds. Some types can grow fully submerged. The leaves of irises are stiff and stand up straight. They have beautiful spring flowers that come in many colors. They help absorb excess nutrients in runoff.
7. Horsetail Reed
Horsetail reed (Equisetum hyemale) is a bamboo-like, moisture-loving plant. It has stems that are always green and have bands of brown and green. Horsetail grows in groups along the edges of ponds, and its deep roots help keep the banks stable. This ancient plant is unfazed by koi nibbles. It filters water and removes toxins.
8. Floating Heart
Floating heart (Nymphoides peltata) is a pretty aquatic plant with small heart-shaped leaves that float on the water’s surface, dotted by small yellow flowers in summer. Submerged foliage under the water provides habitat for fish. Floating heart grows rapidly. It requires regular thinning to prevent it crowding out other plants.
9. Parrot’s Feather
Parrot’s feather (Myriophyllum aquaticum) is a popular oxygenating pond plant. Feathery blue-green foliage adds texture and softens pond edges. Parrot’s feather grows in submerged clumps or trailing out of pots. It can help prevent algae by absorbing nutrients. But it can spread aggressively so containment is needed.
10. Anacharis
Anacharis (Egeria densa), also called anacharis or Brazilian waterweed, is a fast-growing underwater oxygenator. It produces lush bright green foliage that provides food and shelter for fish. Anacharis grows up to 10 feet tall and helps control algae. It flourishes fully submerged in sunlit water up to 15 feet deep. It may need occasional thinning.
When selecting plants, consider your climate and pond conditions. Favor native plants over exotic imports, which may become invasive. Place plants in pots sunk into the pond floor, tiny aquatic baskets, or the pond margins. Include a mix of surface and submerged plants for well-rounded water quality and aesthetic benefits. With the right plants, your koi pond will soon be a thriving backyard oasis!
What are the best oxygenating pond plants?
At Complete Koi & Aquatics, we like the following:
Scirpus Cernuus – Fibre Optic Plant
- Evergreen oxygenator (if the winter is mild) with green stems that look like grass and grow up to 20 cm long.
- From June to August, tiny white flowers show up on the tips of the stems that look like light sources. This is how the plant got its name, “Fibre Optic Plant.”
Myriophyllum Crispatum – Upright Water Milfoil
- This oxygenator can be planted on the edge of the water or fully submerged up to 40 cm deep.
- Perennial aquatic oxygenator with bright green feathery foliage.
- Myriophyllum plant stems typically extend 60cm.
Ceratophyllum Demersum – Hornwort
- An oxygenator that lives in deep water and can grow up to 60 cm deep
- This is a great plant because it can grow in almost any pond because it is completely adapted to UK weather.
- Most of the time floats freely in the pond and dies back in the winter.
- As soon as it gets warmer in the spring, modified stem buds will start to grow again.
Why are pond plants important?
Pond plants are the backbone of a balanced aquatic ecosystem. Plants and trees on land give oxygen to living things on land, and pond plants do the same for living things in water. Aquatic plants photosynthesise, consuming Carbon Dioxide and turning it into dissolved Oxygen. This allows aquatic animals to breathe but also stops water stagnating. It is important to note at this point, that there is a specific group of submerged aquatic plants known as ‘Oxygenators’ which are best suited to this role in a pond. Examples of such plants include:
- Ceratophyllum demersum (Hornwort)
- Hottonia Palustris (Water Violet)
- Myriophyllum verticillatum (whorl-leaf watermilfoil)
- Ranunculus aquatilis (White Water-Crowfoot).
Plants can provide cover and shade for ponds and their inhabitants. This can reduce predation from animals such as herons, by reducing visibility. In addition to this, a well-covered pond rich in shade will often remain cooler. This again reduces algal blooms (as algae thrives in warm water) but also increases oxygen exchange. Plants do better when it’s cooler, so having a mix of plants that grow on the edges, above, and below the water will make the aquatic ecosystem more productive. Great examples of plants which will provide a pond with shade include the likes of:
- Nymphaea (Water Lilies)
- Pistia stratiotes (Water Lettuce)
- Tall marginals such as Iridaceae (Iris)
*TOP 10* Pond Plants YOU NEED TO HAVE!
FAQ
What pond plants do koi not eat?
Koi are ravenous, and they’re not picky eaters! But Eelgrass, lotus, umbrella plants, water lettuce, and water poppy are five aquatic plants that koi fish won’t eat. We recommend getting some of these aquatic plants for your koi pond.
What is the best plant to clean pond water?
Your pond’s water will stay clean and clear thanks to three plants that can filter it naturally. These are Duck Potato, American Pondweed and Pickerel Weed. Below is a description of each and why they make such an excellent contribution to improving pond water quality.
What is the best floating plant for a koi pond?
Lotus plants are known for their large, exquisite flowers and round leaves that float on the water’s surface. They thrive in Koi ponds, offering shade and helping to oxygenate the water. Lotus plants also have extensive root systems that filter the water, promoting a clean and healthy environment for the Koi.
How to keep koi pond water crystal clear?
How to get Crystal Clear Pond Water – Complete GuideThe ultimate aim for any fish pond owner is to be able to view and enjoy their fish. Fit a UV Clarifier to clear green water. Trap the waste, flush the waste. Add some carbon. Add some beneficial bacteria. Change the pond water. Use a flocculant. Shade the pond.