How to balance plants for your garden pond

Some people who have been attracted to the idea of having a water garden, virtually on an impulse, go out to buy themselves a pond liner, a few plants and a few fish. Theyve bunged em in with the honest intention of getting a few more plants and maybe a few other odds and ends at a later date. So it happens that before they know it, the thing has taken off with enough vegetative power to send a rocket into space, and they no longer own a pool, merely a marshy place with the scraggy dead undergrowth of last years reeds marking the spot where it was. If the pool had been planted out properly, it would be virtually self-sustaining, and as long as the fish population remained fairly constant, thoughts of filters (etc) could remain on the back boiler for some time to come.

A pool is more than a place to just keep fish

Ive always advocated water gardens to gardeners on the basis that here was yet another habitat, an opportunity for them to grow yet another range of plants. There was no need to be daunted by water-loving plants; in fact many of them would be quite familiar to many gardeners. Plants like Houttynia cordata, Lobelia cardinalis and the little Sisyrinchiums could be given the opportunity to show how many strings they had to their bow! Although the plants for water gardens are perennials that usually die back in winter, the maintenance would be less than any herbaceous border simply because there was no digging, pricking over, or mulching just a 4 to 5 yearly root division and replanting. But there is a difference in one very important respect:

In a flowerbed you are at liberty to plant what you want where you want, any number of plants. There would be a preferred spacing of plants; too many too closely planted might suffer from competition and disease; too few plants and you may have a problem with weeds, but there is no reason why they could not be all the same species or even the same variety. With a pool or pond, you are effectively creating a little, self-sufficient, self-sustaining world, with all the ingredients interacting constantly; plants and animals, animals with animals and plants with plants, any one ingredient i.e. species of plant or animal cannot exist by itself, or it least if it does then it will quite simply take over the complete pool. Even the most timid and fragile looking water plant reveals itself to be an incredibly opportunistic beast of a plant without any competition.

In this large pool in Somerset the normally very reserved Water Hawthorn, without any competition, was able go completely berserk when unfettered.