Maintaining an ornamental koi pond can be a laborious, expensive but ultimately very rewarding endeavour. Koi keepers should take every step they can to keep their carp healthy and happy, to avoid seeing all that hard work go to waste. One of the best ways you can improve the health and quality of life of your koi is by adding various aquatic plants to their pond, but that doesn't mean you should throw every kind of plant you can find into your pond willy-nilly. Careful consideration is required to choose the right plants for your pond, and it's just as important to place these plants in the right areas to ensure maximum benefit for your carp.

Why are aquatic plants beneficial for koi ponds?

There are a number of reasons why most well-kept koi ponds feature aquatic plant life:

• Aquatic foliage provides valuable cover for your fish, reducing predation by herons, cormorants and other animals that prey on fish.
• Photosynthesis released additional oxygen into the water, keeping your koi healthier and allowing them to grow larger and more vibrant.
• Aquatic plants also filter nitrates from the water for use as nutrients, and the shade they provide keeps water temperature low, decreasing the likelihood of algal blooms forming in your pond.
• If you plan on allowing your koi to breed, aquatic leaves also provide a valuable safe spot for females to lay their eggs.
• Some plants can be almost as beautiful as the fish themselves, particularly in flowering season.

Which plants are best for a koi pond?

Landscaping and garden suppliers offer a vast array of different aquatic plant species to choose from, and the best approach is to choose a wide variety of different plants -- ideally, you should have a mixture of floating, submerged and shallow water plants, to provide maximum cover and versatility, while also injecting some welcome variety into your pond. The following list of plants is far from exhaustive, but lists a few of the most popular choices:

• Suitable floating plants - water lotus, water lily, water lettuce, fairy fern, water clover, dollar bonnet (also known as water clover)
• Suitable submerged plants - fanwort, water purslane (can also be grown as a floating plant), coontail, water smartweed
• Suitable shallow-water plants - water iris, reed mace, umbrella plants, horsetail  

Whatever plants you choose to purchase, make sure that you are well-informed on their needs and growing habits -- some commercially available aquatic plants will not do well in Australia's hot, sunny climate, while others will grow too quickly for smaller, low-maintenance ponds.

You should also bear in mind that your koi will happily nibble away at the plants you place in there to protect them, and slow-growing, fragile varieties can be easily chewed to death by hungry fish. Conversely, hardy, fast growing plants can easily overwhelm smaller ponds, so it's important to strike a balance. If you decide to choose slow growing plants to save on maintenance, you can reduce damage inflicted by your koi by regularly feeding them greens such as lettuce and cabbage, and by protecting vulnerable roots and tubers, either by potting them out of reach of your koi, or by covering them with rocks or aggregate.

For more information, contact a store that carries landscape supplies.