The Plant Lady. Nelson Water Gardens and Nursery

Northern gardeners do not have quite the accelerated growth we experience here in the South. Nevertheless, if I lived further North I would still continue the practice of repotting each year. To understand why this is a valuable horticultural practice is to understand the native habitat of a waterlily.

In nature, waterlilies and other aquatic plants are found growing in water logged or wet soils. Conversely, they are often subjected to periods of drought.

Waterlilies, both hardy and tropical varieties grow in areas that dry up from time to time. During prolonged dry periods, waterlilies survive in the form of hardy starchy tubers. Droughts serve a vital purpose in the vigor of aquatic plants. In a dry periods, the soil now exposed to air changes from slow anaerobic decomposition (decomposition in the absence of oxygen) to rapid aerobic decomposition. During aerobic decomposition the organic matter in the soil breaks down quickly into nutrients. When the rains come again the waterlilies revive and grow luxuriantly in the enriched soil.

We approximate this in our ornamental ponds by repotting aquatics in fresh soil each spring. Repotting serves another purpose...Waterlilies are vigorous growers and need to be divided at this time as well.

Excluding nutrients, water is the most limiting factor in terrestrial plant growth. Not so with aquatics! Since water is abundant most aquatics are vigorous growers. Nutrients become the limiting factor in their growth. Waterlilies, in particular, are heavy feeders. They produce one to several flowers a day and are continuously renewing themselves with new leaves. This incredible growth must be supported with nutrients. In nature, nutrients are supplied by the soil in the pond bottom where roots can seek out more nutrients as needed. Lilies in ornamental ponds are potted and their growth is limited by pot size. The larger the pot the bigger the waterlily will grow. Supplemental feedings in the form of fertilizer tablets have been developed to keep waterlilies in peak bloom.

Fertilize waterlilies once or twice a month during the growing season. At the same time prune the older yellowing leaves. That's all there is to waterlily maintenance!