The winner

Jeff Barton and his American wife Catherine married seven years ago when she was 34. She joined him in his second-floor Surrey flat overlooking the Thames, housed in a sturdy four-storey brick villa that once belonged to Arthur Sullivan, of “Gilbert &” fame. Sullivan’s pleasure grounds had become a park, and his kitchen garden had been divided up for the occupants of the four flats. The Bartons’ patch was not quite on the river nor adjoining the house, and to get there they had to go out at the side of the house, cross a car park and walk through the garden of an adjoining gallery. Their garden had one high wall, a golden robinia tree and not a lot else. On the other hand, they had a fabulous view of it from upstairs.

Now, these two are organised. That’s what you get when a management consultant marries someone from financial services: there would be a garden. So they cut out pictures from magazines: of gardens, of planting styles, of gates, of the work of their hero, designer Christopher Bradley-Hole. They made files on garden machinery and scrutinised the Chelsea show. Then, four years ago, they sat down and designed their garden and Jeff, a computer whiz, plotted it ready to build. “Gardie”, as Catherine calls it, was born.

As with all modern births, there was a video. Jeff set up a camera on a drainpipe outside the kitchen window, taking a picture every seven minutes from April 1 to the middle of May and, in a flurry of skips and mini-diggers and scuttling figures, their new darling appears; only the robinia remains the same. Watch carefully and at one point you can see a little figure slumped against that tree: it’s Catherine, worn out from humping gravel. Jeff was his own clerk of works and project manager, bringing Gardie in on time and on budget: £2,000 for the walls, £2,500 for the plants and £4,000 for paths, irrigation, low-level lighting and shed. Total: £8,500. Result!

Why is this a country garden? Because of its spacious riverside position; because of the charmingly picturesque, apple-bearing, adjoining gardens; because geometric gardens have as much of a place beside country houses as town houses, and because the planting style, within its boundary walls and fences, is definitely country. Rus in urbe. “Modern planting in a traditional layout,” as they call it. For that, read the modern grasses-and-perennials style, on which they took advice, before organising and planting it for themselves.

Within that grid of paths, it’s an extraordinarily soft planting: no evergreens or ferns, but masses of achilleas, echinaceas, filipendulas, globe thistles, miscanthus and Stipa gigantea; all hers. Underneath are crocus, snowdrops, hyacinths and tulips; all his. And every bed is narrow enough to reach the centre from the path. No seats, no pots, no box balls, no bedding; it’s all absolutely simple. Even the surrounding soft grey trellis is not planted. Cool and calm wins the day. Two days’ work a month from Catherine keeps it in superb order in summer, then nothing until the big cut-down in February and a trip to the council tip.

And yet it’s still a heart-lifting garden. School groups have visited and loved it. The designer shed is a delight, and houses rainwater tanks to supply the irrigation system. There are huge beanbags stored in there, so Jeff and Catherine can pull them out and laze behind the miscanthus. The shed came 69th in a shed website competition, Jeff tells me.

We stand at the kitchen window and peer down at Gardie, their little patch of geometry among greenery and the river. “Would you do the same again?” I ask. “Yes. Ish.” And do you really use it, in spite of the tricky access? “Oh, yes. Being in it is the whole point. Especially in the evenings, and whenever there’s a bottle of champagne. And definitely no mobiles allowed.”

The runner-up

All this is a million miles from our runner-up garden in Worthing, Sussex, which belongs to Nigel and Trixie Hall. Theirs is not a fashionable garden, and there is nothing unusual about the plants, but goodness, it works hard at what it does. Never did you see a bigger quart in a pint pot. It’s a miniature landscape garden where not an inch is wasted or unexplored. When the Halls came here 15 years ago, it was a flat garden surrounded by a vastly obese, mixed-field hedge with a few old apple trees. Nigel had worked in engineering, became sick of the whole business and had turned to tree surgery. This garden was his chance to make something living from scratch, and as an ex-engineer, he had the skills to do a pukka job.

He excavated 40 cubic metres of soil and made perimeter mounds to create a little valley with a pond at the bottom, set diagonally across the garden to gain maximum length. Weeping birch trees were planted to command the valley, superbly managed by Nigel to keep them as slender, weeping spires. A lorryload of Purbeck stone was delivered, chosen for its pale colour and used to create rockeries along the valley sides. But the mounds could not be heaped against the garden’s wooden fences, so Nigel built a chest-high wall a yard inside the fences to take the weight of the soil. Then, by planting shrubs on top of the mounds, a boundary screen of 12ft-14ft was achieved. Where most gardens might have predominantly deciduous plantings with evergreen highlights, here it is the other way round to ensure privacy.

Between the wall and the fence there was now a narrow, unused alley where they planted climbers to make a tunnel roof, and set shade-loving hellebores, bluebells, ferns and lily of the valley at nose height under the shrubs. In the valley, Nigel built a wooden pavilion, complete with belfry and wooden bell, to hang over the pond and be reflected in the water, where carp, tench and goldfish circle. A miracle of joinery, it houses the recycling pumps for the pond and waterfall, their sound disguised by the rushing water. “The house might fall down, but not that pavilion,” says Nigel, proudly.

Around the house, too, every inch has been converted into liveable space. A shady pergola and yellow umbrellas hide much of the thrusting conservatory, and the side of the garage has been given a facial to create a trellised, clematis-clad Regency cottage with a pretty “front door”. “Our stable block”, they call it. The greenhouse has also been hidden behind a wisteria pergola, under which are shelves for specimen hostas and ferns, many of which hang in wooden lattice-work boxes like orchids in a tropical house.

The garden is open for the National Gardens Scheme these days, and groups come to paint in it. Nigel is a watercolourist himself, and he and Trixie love to go hill-walking. “But gardening is such an absorbing thing,” Nigel says. “I could easily become a hermit.” “He could, he could,” warns Trixie.