National Garden Scheme: Ponds take centre stage in a prize-winning Dorset patch

Tina has won wildlife prizes for her patch (Davide Keeler)

The dawn chorus is at maximum decibels (thank you rooks for the bass notes – they are the best bits), the first brimstone butterfly has made its wobbly way towards the primroses, and huge bumblebees are fumbling around in the pink flowers of the nectarine, which is in full flower against the wall inside the greenhouse. I'm not going to stick my neck out and say it must be spring, but at least the temperature is gradually crawling up beyond 12C. The year is on the move.

I've been shovelling compost, getting bucketfuls of the stuff round the trees and shrubs with the aim of emptying the bin of old compost, before the bin of new stuff alongside it starts to overflow. They are both 8ft by 6ft so there's a lot to shovel. As gardeners, we mostly think of our compost in terms of what it's doing for our gardens: improving the texture of the soil, adding humus, providing food for the trees and shrubs we've planted.

But Tina Wright, whose garden is open for the National Garden Scheme tomorrow, points out that compost is vital for wildlife, too. She has won wildlife prizes for her patch and has an impressive number of compost bins, eight of them, each measuring 8ft by 4ft.

These are the breeding grounds for larvae of masses of beetles, flies, springtails and other invertebrates. The focus on 'wildlife' in gardens is generally on birds and butterflies and the things we can see. But at the bottom of the food chain are the creatures that no one writes sonnets about, but without which, the bigger things would not survive. Tina rates her compost heaps as one of the five most important features in her wildlife-friendly garden.

Top of the list is a pond, or in her case, several ponds. The first pond she ever had was in the garden of her home in Barnes, before she moved to the country. It was small, less than 4ft by 2ft, but she worried about her small daughter falling into it, so started to bail it out. But when she got towards the bottom of the pond, she found more than 70 frogs. Putting them in buckets, she marched them across Barnes Common to be released in the pond.

But the next day, there were more frogs in the now rather shallow water in her garden, and she started to feel guilty. So she went into reverse and instead of getting rid of the pond, ordered an even bigger one. In her present garden, she has gone pond crazy; the latest is a copy of a design feature she saw at the Hampton Court garden, with water falling in shutes from the wall of the house. All the water features are driven by electric pumps. It has doubled the size of their bill, she says, but for her, the dragonflies, frogs and newts that come to the garden because of the ponds are compensation enough. It all depends on how you add up your environmental sums.

The rectangular swimming pond is thickly planted with reeds and flowering rush (Alamy)

The first pond, in the country garden she and her husband took on 11 years ago, started off as a reasonably simple affair, made in a roughly circular shape close to a boundary hedge. But she made it very much less simple by adding a stream to run into it from a cleverly concealed starting point, way off at the top of the garden. The ground sloped, but not too steeply, and the stream burbles its way down the side of the garden looking remarkably natural.

Its path curves, but not too much and the course, when dug, was fitted with a butyl liner, weighed down and disguised by large pebbles. Either side there are irregular bog gardens, planted with astilbes, ligularias, hostas, primulas and other plants that don't mind wet feet. Tina designed a deck to overhang the pond and filled the space between the ground and the underside of the deck with prunings, rubble, old cardboard and all kinds of other debris that would provide shelter or food for insects in the garden. "It's a good way of getting rid of rubbish, too," she says pragmatically.

Close to the south side of the house is a far more ambitious project, installed, as the first pond was, by Kingcombe Aquacare (kingcombe.com). This is a rectangular swimming pond, roughly 30ft long by 15ft wide, with big shallow filtration beds, thickly planted with reeds and marsh marigold, iris and flowering rush. Behind are the tall, dry, corn-coloured stalks of Norfolk reed (Phragmites australis), an aggressive coloniser but, says Tina, brilliant at its job, which is to sift nutrients out of the water as it moves through the filtration beds to be returned to the pool. On the gravel-filled ledge that runs just below the water along one side of the swimming pond, Tina stands out pots of dramatic, black-leaved colocasias and tropical water lilies. During the winter, these stay safely inside the greenhouse.

The first pond was the one made with wildlife in mind, with the sides gradually sloping from the edge to the centre, as all the wildlife manuals suggest. But Tina has found that most of the creatures in her garden that like ponds, like the swimming pond better than the one that was made specially for them. The swimming pond drops straight down to four feet at either end, sloping to seven feet in the middle. Is it, she wonders, because the water in the swimming pond is too deep for the heron to fish? Have the frogs and newts actually found that the swimming pond, right next to the house, is a safer place to be? Tina shrugs. "They're welcome," she says, "wherever".

Tina's garden at The Old Vicarage, East Orchard, Shaftesbury, Dorset SP7 0BA, is open tomorrow (1-4.30pm) and on 27 April (2-5pm); admission £4, children free

TINA'S TIPS FOR A WILDLIFE GARDEN

1. Make a pond, even if it can only be a small one, for damselflies, dragonflies, as well as newts and frogs.

2. Plant trees and, if you can, leave branches torn down in the gales to rot quietly somewhere out of the way. Many insects depend on dead wood in their life cycle.

3. Make a bug hotel. Tina's are built from pallets with bricks, straw and other debris packed between the layers.

4. Put up bird boxes and bat boxes.

5. Make plenty of compost.