Green, brown grass of home: Anna Pavord on how one woman turned a clay field into a summer oasis

By mid-August, most of the grasses in our newest piece of planting were spreadeagled over their neighbours, stems snapped, heads mangled, the whole scene looking as though a band of malevolent gnomes had played pick-a-stick in the patch. It was a disaster. By the end of August I couldn't stand it any longer. The baptisia was swamped under a load of collapsed deschampsia. The grace of the fabulous cow parsley, Selinum wallichianum, was ruined by the drunken crashes of its neighbour, Calamagrostis 'Karl Foerster'. So what's with all this stuff about grasses and late-summer interest, I asked myself? How do I get these frost-rimmed grassy seedheads if the wretched things have collapsed before late summer has even started?

So I got out my shears and gave the catastrophic plants an angry haircut. They look hideous, like bristly shaving brushes. But at least the other things around them have now got a chance. Geranium 'Rozanne' is not an easy plant to put down but even that had given up under a crash of 'Bronzeschleier', one of the tufted hair grasses, Deschampsia cespitosa. Tufts? These things were thicketed thugs. Where had I gone wrong?

Judy Pearce, of Lady Farm in Somerset, listened sympathetically to my story. "But I've never heard of calamagrostis behaving like that," she said. "Or 'Bronzeschleier'." And through her kitchen window, out of the corner of my eye, I could see fountains of Stipa gigantea growing in happy companionship with pink persicaria, clumps of miscanthus, caringly thoughtful of the bergenia at their feet, and 'Bronzeschleier' waving gently in the breeze and doing, in its elegant way, everything that the books say it should. It was galling, to say the least. But also instructive, because Lady Farm is an extraordinary garden, made over the past 15 years on a scale that takes your breath away.

It drifts in a series of vast, sweeping plantings down the bowl of a gentle valley, taking in two lakes, a ravine, a steppe and two prairies on the way. Though formal round the house, with box-edged beds, lavender and straight-edged lines, most of the 12 acres is informally planted, with massive drifts of miscanthus, lythrum (especially deep pink 'Firecandle'), persicaria, eupatorium and stipa. Most of it, she said, wasn't in any way planned. "I just plopped in all sorts of things that I thought might go."

But for her most recent plantings, two massive borders winding from the steppe back to the house, she did put something down on paper. "It was my favourite occupation. In winter. At night. By the Aga. Your mind is going through all these plants different heights, different colours. You make lists. You cross things out." And, if you are Judy Pearce, you end up with lots of grasses: Deschampsia 'Goldtau' elegant by the lake, the variegated Miscanthus 'Morning Light' standing as straight and true as stone pillars in the corners of the cottage garden, pheasant tail grass, Stipa arundinacea pouring waves of liquid seedheads into the low light of a September afternoon, Molinia 'Transparent' as airily diaphanous as any gardener could wish.

How did it all start, I wondered, given that Judy and her husband, Malcolm, had been milking cows at Lady Farm for almost 20 years before she ever thought of making a garden there. "Well I couldn't before," she explained, "because the farm buildings and the cows were right outside the window. Then we got another farm and the cows went over there. I got in a couple of bulldozers and smashed everything down.

"Then I realised we had a lot of red clay and no top soil, so we moved a field where the soil was really thick. Every day for two or three weeks I stood outside with the two diggers, waving my arms about more earth here, a bit more there, building up banks on the sides to cut the wind. If I'd had a plan, I'd never have started. I ended up with a big expanse of nothing. I covered it all in grass and planted thousands of trees round the edge."

That was the beginning. The rest, she says, came from desperation. Her nagging had been the cause of the cows and the buildings going. She had been totally responsible for the ructions at Lady Farm and felt she ought to do something about it. And what did her husband have to say, I asked. "Oh, he never says no," she replied. "Though he did go a bit quiet for a week when he went down for a game of tennis and found I'd bulldozed the court."

Had she read books before she embarked on this great enterprise? "None," she said. "For years, all I read was Horse and Hound. I grew up wanting only to be a flat race jockey. I rode everywhere with my stirrups up round my chin." But girls weren't welcomed in the sport then, so she became an air hostess instead. "I didn't mind what I did as long as I was on the go." That same energy infuses the garden at Lady Farm. She likes things BIG. Not manicured. Not titivated. It's easier on maintenance, as she points out. But the style also suits where she is, with the garden blending seamlessly with the farm pastures beyond. The stream that feeds the lakes (dug where the slurry pit used to be) was planted in autumn shades of cream and beige and russet browns. But the cows in the field beyond were black and white. "Malcolm," she said. "They'll have to go. They don't fit in." They've been replaced by brown and white Montbeliards. "Much nicer," she says, only half seriously.

Her energy is matched with a wonderfully light-hearted attitude to what she's achieved. She's not precious about the garden. She doesn't labour over the problems, is practical and has a very sure sense of how the garden should hang together. Though it's become an icon of the modern style of planting, she shows no signs of resting on any laurel that might present itself.

She's presently "rubbing out" in her phrase, her first prairie planting. "When I made it, there weren't such good plants around as there are now. And it didn't go with the steppe." This steppe is only three years old, but looks wonderfully settled and integrated: a matrix of Stipa tenuissima and bronze carex tying together Euphorbia cyparissias, thickets of the grey-leaved willow, Salix exigua, silver-blue eryngium, sword leaves of iris, burning kniphofias, small yellow stars of tickseed and occasional giant spires of Verbascum olympicum. It looks fantastic. Back at home, I explained to the shaving brushes what they had to do. Somehow, I don't think they are going to cooperate.

Delfland Nurseries are at Benwick Road, Doddington, March, Cambs PE15 0TU, 01354 740553, www.delfland.co.uk