9 Best Plants For Your Koi Pond

Koi pond garden with aquatic plants

Aquatic plants are considered to add beauty and tranquility to any koi pond. These plants add an eye-catching dimension to your water garden and increase oxygen production significantly.

While the pond plants provide aesthetics to the water garden, they also keep the pond water in cooler temperatures and healthier conditions, particularly in the hot summer months. Moreover, they create a safe environment for aquatic inhabitants.

However, aquatic pets with different species also have varying requirements. Therefore, these plants offer benefits and drawbacks in many different ways.

And for this reason, make sure to select and add the right aquatic plants that can thrive harmoniously with your Kois.

To help you choose suitable aquatic plants for your Koi pond, here are some of the best species that we consider to be excellent choices.


9 Best Aquatic Plants to Grow In Your Koi Garden Pond


1) Water Smartweed (Persicaria amphibia)

Water Smartweed (Persicaria amphibia)
Image by: illinoiswildflowers.info

This plant is not overly picky and can be an excellent oxygenator and cleaner to your pond water. The plant also produces oblong, vibrant flowers from early summer to mid-autumn, adding interest to your water garden.

Better yet, the plant appears to be palatable to the Koi. It provides protein necessary for your aquatic pets. Adding smartweed into your Koi pond can be very beneficial if you want to enrich your fishes’ diet.

Moreover, smartweed is also a food source for aquatic waterfowl, songbirds, quail, doves, and other small mammals.


2) Water Lotus (Nelumbo lutea)

Pink flowering lotus in the pond

Lotus is a hardy floating aquatic plant you can find in most Japanese pond gardens. It exudes elegance while sitting on the water surface yet requires minimal maintenance to grow.

This plant grows best in water temperature that is approximately 75 to 87°F and at least 18 inches deep. This pond beauty prefers low humidity and demands full sun for at least 5 hours a day.

Lotus also occupies plenty of space, making the plant suitable for large size ponds. If you have a small pond, you can choose dwarf varieties to accommodate your plants’ needs.

Planting lotus in a large and wide, but shallow container without holes will keep the plants from overtaking the pond. A 24 to 36-inch diameter black plastic tub filled with 6-8 inches of garden soil works best.

Set the container into the pond and wait for at least 1-2 years for the plant to produce the first blooms. However, the wait is worth it as lotus flowers are truly spectacular.

Koi do not find lotuses palatable. And they provide plenty of shade and a pleasant environment for your aquatic pets, particularly in the hot summer months.


3) Water Lily (Nymphaea)

Blooming white lilies in a pond

Water lilies are handy from tropical areas similar to the lotus with gorgeous and fragrant flowers but with smaller sizes. This aquatic plant can thrive in colder temperatures or with less sun.

Hardy lilies go dormant in winter. And their broad leaves help keep ice and snow at the top surface of the pond acting as an insulating layer that protects your Koi from harsh winds and constant fluctuations of winter temperature.

Lilies are also a floating type that can thrive even with water of several feet only. But it would be best to protect lilies roots when keeping them with Kois.

While the pads undersides serve as the perfect hiding spot for the Koi to lay their eggs, these expensive pets find the plants palatable. They love to nibble both the roots and leaves.

Some pond owners incorporate hyacinth in the pond to provide snacks to Kois.


4) Water Poppy (Hydrocleys nymphoides)

Water poppy with a yellow flower.

The water poppy is an aquatic plant you can grow in any size of pond. It grows best when submerged about 6 inches below the water surface.

The plants feature dark green foliage and produce attractive yellow flowers adding elegance to the pond’s environment.

It grows pretty quickly in the summer and is an excellent choice to add interest to your pond’s rough and unattractive edges.


5) Horsetail (Equisetum hyemale)

Horsetail (Equisetum hyemale)

Horsetail is a hardy aquatic plant you can add along the edge of your pond. It has coarse, jointed, and slender stalks.

Common horsetail (Equisetum hyemale) can grow up to 24 inches tall while dwarf varieties reach up to 8 inches in height. And both types can thrive in regions as cold as Zone 4.

This plant is excellent in filtering the water in the pond and does not overtake the pond’s space.

Better yet, they provide the right shade for your Koi. Also, they don’t find this plant palatable, so you don’t have to worry about it being consumed.

Besides, it is easy to uproot if you find them not suitable to your liking. All you need is to gently pull up the rhizomes if you want them removed from the landscape.


6) Water Purslane (Ludwigia)

Water Purslane (Ludwigia)
Image by: weedid.missouri.edu

Water purslane can be both grown as submerged plants or allowed to float on the water surface. It comes in several species and often produces small sized flowers.

Red Ludwigia is the favorite of most pond owners among all the species. It grows pretty quickly and champions to oxygenate the water in the pond.

This hardy beauty grows best in water or moist edges and prefers plenty of sunlight to thrive.

The plant is considered weedy, but it helps stabilize muddy banks and is useful in filtering out toxins in ditches.


7) Umbrella Plant (Cyperus alternifolius)

Umbrella Plant (Cyperus alternifolius)
Image by: arthropodafotos.de

Umbrella plant is a tender aquatic perennial with foliage arranged on stems like the ribs of an umbrella that feature an easy nature and relaxed habit.

Atop the clump of an erected triangular, the leafy bracts in an umbrella shape appear as small dark brown nut-like flowers.

This architectural plant adds an exotic and tropical feel to the water garden. It also creates a unique background for other pond plants.

And as the native of Madagascar it can tolerate light frosts but not prolonged periods. It performs best in full sun or partial shade in wet soils and can grow up to 3-6 feet tall and 2-3 feet wide.

While the plant prefers and thrives in moist soil, it also grows in standing water up to 6 inches deep that is disease-free.

It quickly multiplies by self-seeding and rhizomes. And planting in containers will help control invasive spread. You can cut back dead stems in the fall to maintain a tidy landscape.


8) Water Iris (Iris pseudacorus)

Water Iris (Iris pseudacorus)

Water iris is another favorite in many Koi ponds. It comes in several species in many different attractive colors.

This vibrant flowering pond plant prefers full sun or partial shade, and acidic but moist soil.

The sturdy and upright branched stalks create an eye-catching bloom in great abundance, particularly from late spring to early summer, followed by large seed pods.

Iris can grow up to 3-5 feet tall and looks spectacular when you plant in groups of about 6-8 plants. However, it quickly spreads rhizomes and forms bigger colonies, so be careful to site to prevent the plant from overtaking the pond.

You can remove seed pods before it reaches maturity to prevent undesired self-seeding. Also, the plant can cause severe discomfort when ingested, so deer mostly ignore this beauty in the pond when looking for their food source.


9) Water Clover (Marsilea mutica)

Water Clover (Marsilea mutica)
Image by: uaex.edu

Water clovers are mud-growing aquatic ferns that are free-floating plants and mud dwellers that grow along banks or in shallow water.

They produce long, freely branching rhizomes that spread the plant along with the mud in sunny spots up to about 18 inches deep.

At each node is a leaf on a slender rachis that connects to the floating frond. The plate-like foliage comes with four leaflets of equal size. And when you look at it closely, it features a vein pattern you can find in the ferns family.

Known as a hairy water clover, this plant releases spores fed on by a variety of waterfowl, and extends tough rhizomes to provide shelter for fish from predators and shade to protect Koi from the sun.


Why Add Aquatic Plants To Your Pond Garden?

A Koi pond, whether big or small needs aquatic plants. These plants provide shade to the Kois and keeps the water temperature cool in the summer.

The Koi fish is considered a highly sought-after ornamental pond fish with its size, colors, and graceful swimming. It comes in attractive species with over 100 different varieties. However, these expensive ornamental aquatic pets have distinct requirements to thrive.

They require water temperatures between 55 and 79°F and a pH of 7.5 to 8 and the pond should at least hold 1,000 gallons of water and be a meter deep.

And incorporating aquatic plants into your Koi pond will not only enhance the surrounding environment of the water garden, but will also offer an array of benefits to your Kois.

Aquatic plants are a great addition to perform vital functions such as keeping the water oxygenated, healthy, and adding elegance to the pond aesthetics.

Besides, they provide shade to protect Koi from the intense heat of the sun and a refuge from various predators.

Moreover, aquatic plants prevent the rapid algal blooms from overtaking the entire pond and aid female Koi to secure eggs underside the leaves.


Methods To Stop Koi From Eating Pond Plants

A beautiful Koi pond garden
Image by: koistory.com
  • Utilize Rocks & Gravel To Substrate

Koi fish love digging sediment, looking for tender roots to nibble on. Plants’ sources that are palatable to Kois can be protected by placing gravel or rocks at the pond’s bottom.

And if your plants do not produce roots or rhizomes that require trimming maintenance, adding a mesh over the stone or rock is also beneficial.

However, this method can be tiring if your plants require frequent root trimming to prevent outgrowth, as you would have to move both the substrate or mesh regularly to cut the plants to avoid the plants taking over the pond.

  • Use Containers and Pots

Another way to protect your plants is to place them in containers and pots before putting them into your pond.

This method will prevent predation and allow the plants to establish themselves so they are able to withstand minimal predation on the lower stems or when new root growth happens.

However, this method is only doable with plants that do not produce extensive rhizomes. Otherwise, plants with persistent rooting systems that spread widely may break your containers.

  • Take Advantage of Plant Protectors

Aquatic plant protectors come in many forms. The bag-like structure made of mesh is the most popular among pond owners. This type of protector is often used to protect floating species such as water lilies.

  • Avoid Fish From Getting Hungry

Hunger stimulates Koi’s desire to dig and look for a food source. Feed your fish regularly with high nutritional fertilizer to keep them full.

Well-fed Koi won’t desire to explore the surroundings to look for new growth roots to nibble.

You can consider homemade Koi food recipes or some pellets with wheat germ content to keep their taste bud varied.

Using various fertilizer types to fulfill their nutritional needs will help keep the fish from looking for tasty roots around the pond.

  • Add Non-Palatable Plants

Like people, Koi don’t find all plants palatable. This pet is also picky about which plant it prefers to eat. And plants like lotus, hornwort, eelgrass, and horsetail are some of those that the Koi does not like to feed on.

Also, choosing plants with thick and tough leaves will give your fish difficulty to consume.

Plants like Watershields have thick leaves and mucilaginous substance that makes them less palatable.

Sagittaria also comes with thick leaves that aren’t easy to consume. However, these plants are invasive and require regular maintenance to prevent them from overtaking the pond.

  • Do Not Overpopulate the Pond

Maintaining the right stocking density is another key element to avoid the plant-eating Koi dilemma.

Koi with vibrant colors are visually delightful when swimming gracefully in your pond garden. However, putting too many will incite the instinct to compete, especially for food.

And finding your ruined water lilies is one of the most common evidence of hungry Koi.

One important thing to remember is when buying small Koi, consider how big they grow when the fish reaches maturity.

Without considering enough room for your Koi, you’re risking the health of the entire pond inhabitants. And this will make your fish suffer and be stressful.

  • Start Small

Another effective method is to have the pond well planted with mature plants before adding large Koi to the water garden.

Another option is to start with small fish about 3-inch in length. This way, the plants can establish roots and withstand minimal predation as the fish grow gradually.

  • Add Barrier Protectors

Adding fences in the pond to protect your plants is probably not ideal, but this method may help if you’re having trouble with your fish eating your plants.

You can utilize mesh, rocks, and shelves in fencing. This way, the pond still benefits from the vegetative aesthetics and oxygenation but won’t function as a hiding place for young fish in the hot summer months.


Final Thoughts

Both aquatic plants and Koi complement one another. And incorporating these two in a pond creates a healthier water garden.

Considering a Koi pond in your backyard adds a sense of tranquility and relaxation to your outdoor space.

Most pond plants are champion oxygenators, help reduce nitrate while others remove toxins better than chemical absorbents. But they all have similarities when it comes to offering coverage from predators.

Yes, plants add interest and function as champion oxygenators and help filter your pond, but they require a consistent maintenance routine to ensure both your Koi and plants flourish.

So, when considering a backyard haven for your Koi, consider these easy-to-manage, best aquatic plants to help provide a delightful environment to your pond garden.

Have you tried adding one of these best aquatic plants to your Koi pond garden? Feel free to share your experience with us in the comment section below.

About Benita Abucejo

Hi there! My name is Benita Abucejo. What can I say? I truly love spending my days in the outdoors, specifically in the garden. Gardening has always been a strong passion of mine since I was a little girl. It has brought me so much joy and happiness that it is definitely safe to say that I will be a gardener for life. For a period of time, I was able to work with people who are into home gardening and I found it to be quite beneficial to my physical health, as well as my mental well-being. Here at Seasonal Preferences, I am going to share with you my experience and ideas so that you can fulfill yourself with the same satisfaction and happiness. Of course, if you have ideas, I would love to hear those as well! Being creative in the garden can really be quite fascinating so let's share our experiences and be the best gardeners we can be. With that being said, thank you for dropping by and please leave me a comment on one of my posts if you would like to get in touch!

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