Desmond FitzGerald wants to talk about his garden and the ideas behind it, but all I want to do is walk round and round his fine, giant echium. Poised next to one of the winding paths, it is a benign, pink-and-grey rocket ready for take-off. Its perfect, 12foot nose-cone is evenly studded with pink tubular flowers, and the bees working through them make the whole structure hum.
It's a hybrid echium, a cross between the coarse, monstrous Echium pininana and the more tender, grey-foliaged Echium wildpretii. It should have suffered frost bite to its long strappy leaves during the last cold spell, but this Dun Laoghaire front garden has an especially clement microclimate, tucked away at the end of a terrace and nestled in between two big pittosporums. Once you have inspected the remarkable echium, you are free to notice the equally remarkable house behind it. A stern, uncompromising building constructed in 1945 in the International style, it's a white, flat-roofed rectangle divided into further rectangles and squares. Something about it is reminiscent of the seaside: its coolness making it like an outsize block of refreshing vanilla ice cream, and a column of port-holes lending it a nautical air.
But whatever about it, this brave, austere building requires a special kind of garden: one that complements its strong horizontal lines with some vigorous verticals, and that counterpoints its controlled precision with a bit of offbeat chaos.
Desmond FitzGerald, an architect and part-time lecturer in landscape architecture at UCD, found just the right brain-fodder for the garden in the early 20th-century paintings of Henri Rousseau, a naive artist whose exuberantly mad jungle scenes also inspired the gardens at Creagh in west Cork. The laugh of it is that Rousseau, who worked as a customs official, had never been near a jungle in his life, and the extravagant, lush plants that populated his tropical, steamy canvases were copied from the Paris botanic gardens, the Jardin des Plantes.
Desmond FitzGerald's garden is roughly modelled on Le Reve, a fantasy where wild beasts peer out between green, exaggerated leafforms at a curvaceous, lounging nude. In this modest Irish garden a small ginger cat does its bit as the fierce animal among the still-juvenile exotic plantings (and when I visited last week, I didn't notice any naked ladies - but, this patch being clearly visible from the road, maybe that's just as well).
Prominent in the Rousseau painting are plumes of the South American saffron spike (Aphelandra squarrosa): in the FitzGerald garden these have been translated into tall bearded irises of bluey-purple and of that flesh tone peculiar to the genus - a colour somewhere between expensive silk lingerie and artificial limb. More look-alike outlandish vegetation is to be found in the shapely forms of plants such as sword-leaved phormiums, spiky yuccas, cut-leaved cardoons and the heavily serrated Melianthus major or honey bush.
The flowers have been kept mainly to a cool palette of blues and pinks: dark-blue hardy geraniums, deep-purple columbines, magenta Gladiolus byzantinus, starry azure camassias, and early in the year, a sprinkling of forget-menots. The two pittosporums, a massive columnar holly and a number of younger specimens - cordyline, Italian cypress and bamboo - give upright accents, along with the echium obelisk (which will die after this one virtuosic, pink swan-song).
The bold and unbridled planting is not just a lavish foreground to set off the rigid, still house behind. Unusually for a front garden, this is a place where lots of human activity is welcomed. "I like to design something with the idea that children will be using it," says FitzGerald. And a network of paths flows through hummocky island plantings, like a blue limestone and gravel delta. The children, Thomas and Kate, like nothing better than sailing around on their bikes: from front gate to side gate to front door to uncharted tributary along the boundary. "Perhaps this garden is too child-friendly" says the designer thoughtfully.
As Desmond FitzGerald admits, the garden is a work in progress, with paths still being laid (and unlaid, and laid again by the children), and new notions still being formulated. "I get great ideas," he laughs, "but I don't have green fingers. I'm disastrous at propagating things." Fortunately he is married to Catherine Earls whose fingers are amply emerald-tinged: "she really is the mainstay, it wouldn't be here without her."
Desmond FitzGerald Architects, 4 Albert Terrace, Crofton Road, Dun Laoghaire, Co Dublin. Tel: 01 2809552; fax: 01 2809557.