Gardening, once seen in Ireland as a fuddy-duddy pursuit, is now trendy, and 'okay to do', says Helen Dillon, who is to be honoured by the Royal Horticultural Society in June. Eileen Battersby tours the glories of the Dillon garden and can't resist running her fingers through the compost

Helen Dillon zealously maintains that no garden plant simply dies; it is usually helped on its way by a gardener, as often a caring one as a neglectful one. 'One of the most spectacular plants I ever killed was a peony.' Photograph: Peter Thursfield

January is surely the harshest test for any garden. Yet the sun shines, albeit with a wintry muted light, on Helen Dillon's masterpiece at 45 Sandford Road in Dublin's Ranelagh. It is a study in elegance which testifies to the harmony of art and science within nature. On any day, in all weathers, there are at least seven gardens to view here, with hundreds of variations in the course of a year. Dillon, a relentless perfectionist who will be honoured in June by Britain's Royal Horticultural Society, patrols her garden with a mother's strict, loving eye.

Unlike many master gardeners, she is generous with her knowledge. Within moments of meeting her she has mentioned her two mentors: the late David Shackleton, once the master of another famous Dublin walled garden, that of Beech Park, Clonsilla; and Graham Stuart Thomas, author of the classic Perennial Garden Plants or the Modern Florilegium (1976), of whom she says: "He's a gardener as well a brilliant plantsman." A bearded light blue Iris he gave to her resides here.

For all the formality of her garden, with its magnificent centrepiece, a perfect lawn, it has not been beaten into submission. Instead, it displays a relaxed if disciplined personality, having been more indulged than tamed. Admittedly there are no traces of children or dogs rampaging through it either. Sir Reginald, the Dillons' dachshund, is built so close to the ground he tends to avoid wet grass and foliage. While Dillon carefully sweeps the slightest few particles of earth into the nearest flower bed with her hand, her eye ever searching for any possible imperfection, she sustains a conversation ranging from the manifold delights of hellebores, to the first sighting "in the 28 years I've known this garden, of a goldcrest" and her pride in having now survived a year without smoking. "And I was a 70-a-day woman; I was really disgusting."