Plants are an essential part of a koi pond, adding beauty, balance, and protection for the fish. By growing aquatic plants, you help regulate water temperature, filter impurities, and increase oxygen levels.
Their leaves and blooms also bring vibrant colors that make your pond feel alive. A well-planted koi pond not only looks more natural but also creates a healthier environment for your koi to thrive.
Some species float gracefully on the surface, while others root along the edges and add structure. Let’s explore 10 of the best plants to make your koi pond both stunning and sustainable.
#1 Water Hyacinth
Water Hyacinth is a fast-growing floating plant that adds a soft, natural look to your pond. Its glossy green leaves form rosettes that float on the surface, while lavender-blue flowers rise on tall stalks in summer.
This plant helps shade the water, keeping temperatures cool and algae growth under control. You can simply let it drift on the pond without planting in soil.
It multiplies quickly, so thinning it out is important to prevent overcrowding. With regular care, it creates both beauty and shade for your koi.
#2 Water Iris
Water Iris stands out with its tall, sword-like foliage and striking flowers in colors like blue, violet, and white. It grows best along the shallow edges of ponds, where its roots can anchor in damp soil.
The flowers bloom in early to midsummer and attract pollinators while adding color. Plant them in baskets submerged at the pond edge to keep growth contained.
They also help filter excess nutrients, improving water clarity. This plant gives your koi pond a graceful, vertical accent.
#3 Water Poppy
Water Poppy brightens the pond with heart-shaped leaves and cheerful yellow flowers. Each bloom lasts only a day, but new ones appear daily through summer. It grows best when floating on warm, shallow water.
You can anchor it in soil baskets or let it float freely. Its roots help absorb nutrients, keeping water conditions balanced. The contrast of dark leaves and golden flowers adds charm to any koi pond.
#4 Water Lily
Water Lilies are classic pond plants, admired for their wide, floating leaves and vibrant blossoms. They come in many varieties, with colors ranging from white and pink to red and purple.
These plants help shade the water, which prevents overheating and reduces algae growth. To grow them, plant rhizomes in pond baskets and submerge them about 12 to 18 inches below the surface.
Remove old leaves and faded flowers to keep plants healthy. A koi pond with blooming lilies always feels serene and inviting.
#5 Horsetail
Horsetail is a striking plant with tall, reed-like stems that add structure around pond edges. Its jointed, dark green stems grow quickly and create a bold, architectural look.
This plant prefers moist soil and shallow water, making it ideal for marginal planting. You can grow it in containers placed at the water’s edge to control spreading.
Its upright form also provides shelter for koi near the surface. Horsetail gives your pond a distinctive, almost sculptural touch.
#6 Water Lettuce
Water Lettuce forms rosettes of soft, velvety leaves that float like open heads of lettuce. Its thick foliage shades the water, helping to keep it cool for koi. The dangling roots below provide excellent hiding places for young fish.
Place a few rosettes directly on the pond’s surface, and they will drift naturally. Because it multiplies quickly, thin out excess growth to maintain balance. This plant is as practical as it is attractive.
#7 Water Smartweed
Water Smartweed adds both beauty and function to ponds with its floating leaves and upright pink flower spikes. Its blooms attract pollinators and hover over the water’s surface like little candles.
Plant it in shallow water or along the edges where it can spread naturally. The plant also improves water quality by absorbing nutrients.
To keep it manageable, trim it back if growth becomes too dense. It gives your koi pond a wild yet colorful feel.
#8 Water Purslane
Water Purslane is a fast-growing oxygenator that benefits both fish and water clarity. Its small leaves and delicate flowers add texture to the pond’s edge. You can plant it in shallow soil baskets or let it float in the water.
Regular trimming helps prevent it from overtaking the space. It produces oxygen during the day, which supports koi health. Simple yet effective, this plant works well in natural-style ponds.
#9 Umbrella Plant
Umbrella Plant offers an exotic look with tall stems topped by clusters of green leaf spokes resembling umbrellas. It grows best in shallow water or damp soil along pond edges.
The plant thrives in warm, humid conditions and adds height to the background. You can grow it in large containers to keep it contained.
Its dense foliage also improves water oxygenation and gives koi places to hide. This plant brings a tropical accent to any koi pond.