Little Italy: Broadwoodside proves that a well-designed garden can look beautiful all year

Was it perverse to ask Robert and Anna Dalrymple if I could visit their garden in late autumn, when the roses were finished, the long borders drained of colour and the trees beginning to drop their battered leaves? No. A well-designed garden should be as pleasing in winter as it is in summer, when the set dressing has been whisked away.

Robert Dalrymple is a designer of books, and though there's no infallible reason why a man who can turn out a handsome book can also lay out a good garden, I assumed that he must have an eye for what looks right. And so it turned out.

The Dalrymples' garden, Broadwoodside, in East Lothian, is made in and around a group of low, stone buildings, remnants of a farm on the ancient Yester estate. The oldest bit is the farmhouse, built in the late 1600s, with an inglenook fireplace big enough to live in. The rest – barn, cartsheds, animal shelters – came later. When they bought it, about 15 years ago, the buildings enclosed a roughly rectangular space but with two draughty gaps. The first thing architect Nicholas Groves-Raines did was to plug them. Now you come into the courtyards which form the heart of the garden through a new arched gatehouse, blocking off the wind that previously hurtled in from the north-west.

It's a very human response, this feeling of relief at coming into a place that shelters you from the elements. But the delight had started much earlier, as I was coming down the track towards Broadwoodside. The first thing you see are two long, strong lines of columnar hornbeams, centred on an ochre-coloured corner tower with an ogee roof. As I later learnt, the building was the architect's handsome solution to plugging the second gap in the original steading. But the avenues, the ochre of the building behind them, the long lines drawn in the landscape; it was like being in Italy, not Scotland.

The hornbeams, or rather the money to buy them, were a present from Robert Dalrymple's grandmother. "She was 90 at the time. She said she'd never live to see them as proper trees. But she's 103 now, and look at them." The restraint evident in the way this apron of ground below the house is set out turned out to be a key feature of the planting at Broadwoodside. When the Dalrymples decide to use a particular plant, they use a lot of it. Hornbeams are set alongside the track leading to the house as well as in the avenue. Clipped balls of Portugal laurel in two parallel lines march across the grass at right angles to the hornbeams. You begin to understand that symmetry is important here.

The garden is made all around the buildings, which are set in the middle of a long, thin piece of ground. The top boundary is marked out by an ancient double avenue of lime trees, planted either side of a track that was once the main road to Edinburgh. From that top boundary, a long line runs all the way through the centre of the garden: through the gatehouse, the courtyards, the long, thin pond in the kitchen garden and out of the door at the bottom to emerge by the balls of Portugal laurel. The line is the spine of the garden and at the head is an eyecatching monument – three immensely slender slate pyramids, grouped together – the first of many installations Robert Dalrymple has brought into Broadwoodside.

The top grassy half of the garden is laid out in long lines of beech hedge, an army of topiary squares and long, narrow borders of Iris sibirica. But from here, you mostly want to look out, over the ploughed field alongside, to the otter-smooth outline of the Lammermuir Hills against the sky. And down to the pantiled rooves of the farm buildings, which surround the heart of the garden.

The way in to this heart is through the new gatehouse. This brings you into the first courtyard, divided chequerboard fashion into 25 equal squares. In the centre is a handsome wooden aviary where the Dalrymples' grey parrot lives. Picture the pale squares of the chequerboard as immaculately-edged turf and the dark ones planted with mop-headed Norway maple (Acer platanoides). Underneath the trees are mats of differently-textured ground cover: dark, grassy ophiopogon, woodrush (Luzula sylvatica), shiny pachysandra, wall germander. "We live looking out on to this courtyard. It's got to look pleasing all year through."

As he's the first to point out, Robert Dalrymple is a great borrower. The chequerboard idea came from designer John Stefanidis, whose Dorset garden he saw in a book. The aviary is a scaled-down version of fruit cages originally designed for Ascott House in Berkshire by Arabella Lennox-Boyd. The idea for the clipped balls of Portugal laurel that I'd seen on my arrival, came from The Devonshire Arms at Bolton Abbey, the long bed of iris from David Wheeler's garden near Presteigne. But the key is to know how to knit together the various borrowings to make a satisfying whole. Otherwise it's a jumble sale.

Nor is Dalrymple a gardener, another thing he's quick to make clear. He has the ideas. Gardener Guy Donaldson does the work, ticking off the jobs written by Dalrymple in a series of big books, all of which they've kept. The formality of much of the design demands high standards of maintenance. I particularly liked the way the grass was cut away from the edges of the squares in the courtyard, the narrow strips turning themselves into shining little moats when the ground is too wet to sop up any more rain.

The second courtyard is classically divided with cross-paths into four grass plots. When I was there in late autumn, a whole row of enormous blue agapanthus, the most tender, broad-leaved kind, were still standing against the house wall, almost bursting out of their pots. It was a wonderfully extravagant gesture, like the gilded ball that shines on top of the bleached burr elm trunk, washed up on the beach at Tyninghame and brought here to decorate the lawn in the narrow south garden.

Wide double doors open in the middle of the end wall in the second courtyard to lead you through to the bottom enclosure, beyond the buildings: a long pool, surrounded by a woven willow hedge, a very necessary greenhouse (it is Scotland after all, though Dalrymple has almost persuaded you it isn't) and neat rows of raised beds for veg. Leave that and you are with the hornbeams again. And it was only at this point, on foot, rather than in the car, that I realised why they made such an impact when I first saw them. They are very cleverly set out, a third wider apart at the lower end than at the top by the building. It's an old trick, but difficult to bring off successfully. "Yes," said Robert Dalrymple somewhat ruefully. "We replanted those trees three times before we got it right."

Broadwoodside, Gifford, nr Haddington, East Lothian EH41 4JQ will open for Scotland's Garden Scheme on 2 June (2-6pm), admission £5. For more information, visit broadwoodside.co.uk