Gardens: Ethie Castle, Inverkeilor

Created over the past eight years by Kirstin de Morgan, who moved to the "unloved" sandstone castle in Angus in 2002, this garden has been landscaped to include a variety of different spaces which blend perfectly into the traditional, rural setting. It is also testament to one woman's determination to turn a vision into reality.

On her first day at Ethie, Kirstin climbed the spiral steps to the Edwardian folly overlooking the garden and spread out a picnic lunch for her then husband and their two teenage children.

The view – of a one-and-a-half-acre bit of flat land which had been used as a chicken run – might have been daunting to some, but Kirstin was elated. Even the three-acre walled garden beyond, once used as a market garden, the dilapidated Victorian glasshouses and rows of 40ft conifers did not dent the enthusiasm of this self-confessed novice gardener.

"I just loved the idea of a challenge," she admits, explaining that she remained committed to the project despite the later collapse of her marriage.

Parts of Ethie Castle date from the 14th century and it was once owned by the Earls of Northesk. Situated just four fields away from Lunan Bay, it is surrounded by open farmland and approached by a winding, single-track road. The isolation ensures a calm and peaceful atmosphere, reflected in the woodland surrounding the informal Victorian loch, the first part of the garden you see on arrival at the castle.

Lawns and lavender-filled beds – "the scent in summer is overwhelming," says Kirstin – frame the castle and set the scene for the back, where the striking formal box-edged parterre flows out from the formal lines of the castle. "I knew I wanted plenty of structure but informal planting," she says.

Her brief was interpreted by Fife-based landscape designer Michael Innes, who laid out the intricate parterre in a symmetrical design of geometrically shaped box-edged beds centred on a raised stone fountain. Divided by gravel paths, many of the perennials-filled beds are punctuated for height by clematis-covered wrought iron pyramids or silver weeping pear, Pyrus salicifolia.

The ancient yew that dominates the east side of the garden was retained and adds an established feel as does the row of yews opposite. At Kirstin's request, a line of beds close to the castle were filled with roses in memory of her father, who loved them. Kirstin is responsible for looking after them. "My designated job is deadheading," she says.

The quantity of materials and plants organised gives some idea of the scale of the works: 1,020m of box hedge, 850m of timber edging, 850m of new plantings, 100 tons of hardcore and 60 tonnes of gravel. Despite the mud and the mess Kirstin found the process very exciting.

"I loved it," she says. "It was almost like a pregnancy, with plenty of turmoil and upheaval and then it was all done and there was new life."

Chosen for the length of their flowering season, plants include a range of May-flowering tulips – black queen of the night and white triumphator, followed by hundreds of purple alliums in all shapes and sizes, as well as varieties of blue mecanopsis. More roses cover the background walls.

A row of established yews was retained to the west to help filter some of the harsh sea winds, and on the far side of the informal woodland garden the perimeter has been planned with a mixed hedge of beech, hawthorn and wild roses.

Although it has been slow to establish, Kirstin hopes the hedge will eventually provide further protection from the high winds and sea air. The high rainfall also presents problems as do the clay veins running through the garden.

A dramatic wrought-iron gate – commissioned and assembled in Ho Chi Minh City – leads into the three-acre walled garden, built in the late 18th century. Here, in a series of raised beds in front of the greenhouse, Kirstin grows the wide range of vegetables she uses in the preparation of food for her B&B guests.

Tomatoes, grapes and chillies are nurtured in the restored greenhouses. Flowers grown for the house include varieties of dahlia, lily and gladioli, "there is nothing more cheerful than a big vase of dahlias", and the smaller pom-pom dahlias "that make you smile", she says.

The remainder of the walled garden is laid out to lawns divided by gravel paths and edged with young hedges. Although Kirstin would like to complete the picture and plant the squares, she is realistic enough to know that such a project would involve too much maintenance. For the moment she is content to enjoy the restful atmosphere created by so much calming, open space that allows the mind to speculate on former glories.

On a practical note, the family collection of hens is housed in a spacious run tucked in just behind the walled garden.

Admitting that she is proud of what has been achieved, Kirstin laughingly says: "I am the worst person to have a garden because I know so little, but I have a wonderful gardener to help me. I find solace in the garden, and one of my greatest pleasures is harvesting the vegetables. Sitting in the summerhouse with a glass of wine on a warm summer's evening is just wonderful."

A further and unexpected measure of the success of this project lies in its attraction to wildlife, especially birds. "When we came here it was silent, now you can hear the constant birdsong," says Kirstin.

Ethie Castle Garden, Inverkeilor, by Arbroath, Angus, is open under Scotland's Gardens Scheme on Sunday 13 June 2010, 2-5pm. B&B with dinner included is also available (01241 830434).

This article was first published in The Scotsman on Saturday, May 29, 2010