7 Best Plants for Koi Ponds

A small koi pond, like most residential ones, needs at least 70% of its surface covered in plants. The plants help to provide hiding spots for the fish. Plants also help your fish to stay cooler.

While a bigger pond does not need as many plants, they still play an essential role in keeping the water clean. The great news is that you have many choices in water plants for your koi pond. In this guide we’ll cover 7 plants that are perfect for Koi ponds.

Water Lily

There are at least 70 species of water lilies, so one is probably perfect for your pond. Some can grow up to 10-feet across, but there are many smaller varieties. Most options will not grow more than 6-inches tall. Water lilies usually bloom in the spring, and they can be grown from zones 4 to 10.

Water Hyacinth

Water hyacinths will bloom from mid-summer through the early fall in zones 9 to 11. This plant has inflated, glossy-green leaves that help it to float. It puts on flower spikes up to 9-inches tall above its foliage, with each spike having about 12 flowers. Be sure that you plant this one in the right environment because it can overtake all other plants, especially in warmer climates.

Water Lettuce (Pistia stratiotes)

This plant thrives in zones 8 to 10. It often spreads to be 18-inches wide and 6-inches tall. Velvety, overlapping leaves produce rosettes that resemble open heads of lettuce. This plant puts on yellowish-green to creamy-white flowers that are hard to see amidst this plant’s thick foliage in mid-summer.

Water Smartweed (Persicaria amphibia)

Growing up to 5-feet tall, the leaves on this water plant grow up to up to 8-inches long. The upper leaves often float on the water’s surface. One or two flower spikes are found in the spring on top of this plant. The perfect flowers consist of five pink sepals, five white filament stamens, and pink anthers. This plant can be grown from zones 3 to 10.

Water Poppy

Growing in zones 9 to 11, you are likely to love the shiny, dark-green, heart-shaped leaves on this plant. The leaves create a beautiful contrast in the summer with the yellow, three-petaled flowers that can be up to 2-inches in diameter. While flowers typically last for only one day, this plant will continuously bloom throughout the summer. This plant spreads by sending out plant runners to establish new plants.

Water Iris

Blooming in early and mid-summer, the water iris grows well in zones 4 to 9. This plant that grows up to 4-feet tall produces sword-shaped, green leaves that can be up to 24-inches long. These linear leaves have a very prominent midrib. You can find single, double or peony-shape varieties of this flower in a diverse number of colors, including blue, lavender, pink, white and violet.

Horsetail (Equisetum hyemale)

This bamboo-like plant thrives in zones 4 to 9. It produces dark green stems above its rhizomes. Tiny leaves surround each stem that creates an ash-gray toothed sheath. Pinecone-like fruit up to 1-inch long appears at the top of each stem. This sun-loving plant reproduces by spores. Try collecting the leaves as they work very well to polish silverware and cookware.