Surrounding Helen Dillon's elegant 1830s house in Dublin are effervescent borders of pinks, reds and blues. As Robin Lane Fox discovers, hers is a garden painted with bold artistry and a plantsman's feel for harmony and balance.

Dierama pulcherrimum 'Blackbird'

It is an open secret that Helen Dillon's town garden in the Ranelagh district of South Dublin is a horticultural tour de force. It is actually my favourite smallish garden. What is less known outside Ireland is Helen's own style: in her writing, in her borders and in the flesh. Like all gardens, hers has its history and curiosities. So does she, and readers of her splendid book Helen Dillon on Gardening will soon feel that they know them.

You might think from dreamy photographs of its myrtles and celmisias that this garden is in a specially favoured microenvironment. In fact, the climate here is not particularly mild by Irish standards and the soil is very hungry and dries out easily. The surrounding walls are no more special than those in many town plots and despite the acid-loving celmisias, the garden is slightly alkaline. After 27 years of gardening on a now densely planted half acre round the 1830s house, she does not think she has made the job easier. As seriously keen gardeners know, serious gardening causes its own problems. The soil here needs to be fed constantly to support it thick canopy: cow manure and Osmacote are the Dillon garden's main dressings. Potted plants from nurseries have also landed Helen with unwanted pests; vine weevils have arrived unannounced in the past and now behave "as if they are on steroids". But she knows her enemies: "if you're ever in a garden where the owner insists that they haven't got vine weevil, take a look at the bergenias. The tell-tale signs of a visit from the 'ticket collector' (the adult vine weevil) will be there for all to see, in the form of neat bites around the edges of the leaves. The holes in the middle of the leaves are due to snails."