GARDENERS are caring, sharing, nature-friendly types and these days it's common for anyone with the space to spare to set aside a wee corner for a Natural Garden (weeds proliferate, giving a home to a few butterflies and the odd mouse, wonderfully labour un-intensive) or a Natural Pond (habitat for, hopefully, dragonflies, frogs, newts etc, rather less labour un-intensive). Amazing, really, that natural ponds (as opposed to Natural Ponds) work as well as they do, given their total lack of butyl liners/oxygenating plants/carefully selected and mutually beneficial inhabitants.

And all these things are necessary; but the first step is digging the hole. The strong or foolhardy may be tempted to kick off with a spade. Ha ha ha. If the pond is to be a pond rather than a puddle, it needs to have an area of at least 40 square feet and be two feet deep. Hire that digger! And don't forget to leave a substantial shallow shelf around the edge to stand smaller plants on, or they will disappear below the surface, bubbling pathetically like alien swamp creatures, and drown in the murky depths below.

Simply digging a hole then filling it with water creates not a pond but a wallow. The hole has to be waterproofed. Formal, squared-off ponds can be lined with concrete. Roundy ones can be waterproofed with one of those weird-shaped plastic things from the garden centre that look like giant kidney bowls. But the preferred option is a butyl liner, rather like a large rubbery groundsheet. Lurking sharp stones will create a nasty sieve effect and hence a swamp effect from underneath the liner (highly undesirable).

If the hole has inadvertently been dug on a slope, filling the pond is the point at which the horrible truth manifests itself (symptom: water welling across the rest of the garden, taking with it mud, seedlings, the pet rabbit, the lawn, etc).

But then comes the fun bit: adding all the lovely plants and fish! Most water plants look like bits of stick in pots of mud when they are bought. It requires a great leap of faith to believe a nasty-looking blob will eventually be a waterlily. Water plants need to stay in their pots and be firmly anchored. How to put a plant in a pot in the middle of a two- foot deep pond without (1) getting very wet and without (2) all the earth floating out of the pot is a tricky problem. But not one to worry about unduly, because after all this effort the fish are likely to start by eating the plants before graduating to eating each other. Once a passing heron has mopped up the remaining (very fat) fish, the lucky gardener can start all over again.