From the viewpoint of the water lily, the pond is both a home and a constant battlefield for resources. We, the plants, engage in a silent, continuous effort to convert sunlight into energy, stretching our roots into the nutrient-rich substrate to fuel the growth of our magnificent pads and blooms. The presence of fauna, particularly large and active koi fish, introduces a variable that can disrupt this delicate balance. While we do not experience fear in an animalistic sense, our survival is threatened by physical damage that hinders our photosynthetic and reproductive capabilities. A harmonious pond is one where the fauna respects the flora, allowing both to thrive without one compromising the existence of the other.
Koi are opportunistic omnivores with a natural curiosity that leads them to nibble on almost anything in their environment, including aquatic plants. They do not typically seek out healthy, mature water lily leaves as a primary food source. Their interest is often piqued by tender, new growth—the young shoots and buds that are most vital for our expansion and reproduction. Furthermore, koi will root around in the substrate at the base of the plant, dislodging our roots and tubers in search of insects or other food, causing significant indirect damage by destabilizing our anchor to the pond floor. This foraging behavior can uproot young plants entirely or weaken established ones, making us susceptible to disease.
The most effective strategy to protect our root structure is to physically separate it from the koi. This can be achieved by planting the water lily tuber in a sturdy, wide-based planting basket. The critical additional step is to thoroughly cover the surface of the soil with a layer of large, smooth stones or river rock. This barrier prevents the koi from being able to dig into the soil and disturb our delicate roots and rhizomes. The stones should be too heavy for the fish to move and large enough that they cannot be accidentally dislodged during vigorous feeding activity. This method allows us full access to water and nutrients from the soil while keeping our foundation secure from prying mouths.
Our leaves and flowers can be safeguarded by utilizing our own natural growth habits. Koi are less likely to bother foliage that is difficult to reach. By planting our pots at a sufficient depth—generally at least 18 to 24 inches below the water's surface—the majority of our leaf stems will grow long enough to place the pads on the surface, far from the casual nibbling of fish near the bottom. Additionally, allowing us to establish a strong presence before introducing fish is beneficial. A mature water lily with a large spread of leaves will be more resilient and can better withstand occasional investigation than a vulnerable, newly introduced plant. The dense coverage of pads also helps shade the water, reducing algae growth and creating a more stable environment for all pond inhabitants.
A primary reason koi explore and nibble on aquatic plants is due to hunger or a lack of sufficient dietary variety. To divert their attention away from us, it is crucial that they are provided with a nutritionally complete, high-quality koi food offered in regular feedings. This satisfies their primary hunger and reduces their instinct to forage amongst the plants for sustenance. A well-fed koi is simply less motivated to sample the landscaping. This, combined with the physical barriers, creates a comprehensive defense system that allows both the vibrant fish and the lush aquatic plants to coexist and contribute to a healthy, beautiful pond ecosystem.
