Gardens provoke a mixed bag of emotions. They play a tune on the senses (at a geometric Italianate garden, for instance). They induce light-headed elation (a herbaceous border in full flight). They provoke sharp envy (a coveted rarity). They command gentle peace (calming water). The garden-lover gets used to, and welcomes, being manipulated like a button accordion.
But despite being happily swayed and dipped by a many-mooded horticultural medley, I can't remember ever wanting to cry at anything I experienced in a garden. That is, until I encountered the work of Dutch plantsman and designer Piet Oudolf. His rhapsodic plantings of muscular, hardy perennials and energetic, mobile grasses bring tears to my eyes, make me weak at the knees and swell my heart to bursting.
This, I am pleased to learn after speaking to Piet Oudolf a couple of weeks ago, is the sought-after reaction. His ebullient landscapes - populated by crowded spires of foxgloves, snaking heads of veronicastrum, dusty plates of sedum and light-swept grassplumes - are designed to free the spirit and release emotions. They fulfil a longing we all have, but one that is especially felt in built-up cities and soulless public places. In such an environment there is "so much need for emotion and the more intimate things, and the things that flowers and plants do to a person . . ."
But the pity of it is, Oudolf says wryly, that "big landscape designers who work in urban developments think more in terms of `hardware' than in `software'."
Oudolf's "software" materials are hundreds of varieties of perennials, grasses and bulbs, and interesting shrubs and trees. Often, the clipped shapes of box or yew make a sombre, solid counterpoint to the never-ending movement and constant change of the other, performing plants.
Piet Oudolf is a keen observer of plants, and has established a nursery, now run by his wife, Anja, at their home near Arnhem. Her numerous new varieties are bred. As well as grasses - for many years one of this designer's signature plants - there are Oudolf cultivars of astrantia (masterwort), sidalcea (prairie mallow), filipendula (meadow sweet), monarda (bergamot) and salvia. All share a certain guileless quality that gives an abandoned and nature-let-loose look to Piet Oudolf's magnificent plantings.
"You look for the wildness in a plant, but you also look for its `well behaviour'. You look for plants that have personality or character," Oudolf explains. "Every plant you meet . . . I call it `meet the plant', you see it as a character or person, and you want to know it and grow it and see the positives and negatives."
The 55-year-old designer, who (lucky for us) chose not to go into his family's restaurant and pub business, is gradually assuming his rightful place as one of today's creative garden geniuses. The Royal Horticultural Society has shown its approval by commissioning a 150 metre-long border at its flagship garden at Wisley. "It is a new concept," says Oudolf. "Long streams, diagonal streams of plants. Difficult to explain. I don't explain because you will get a picture that is wrong."
In Holland, meanwhile, Amsterdam last summer opened an Oudolf garden with grasses and perennials - "not too tall, and caterpillars of box clipped in an organic way". Again there are plant streams, "but different from Wisley".
Piet Oudolf shares his ideas in two books which he has co-written, Gardening with Grasses and Designing with Plants: both are endlessly inspiring. But if you're after a more three-dimensional encounter than picture-and-print on page, you have the opportunity to catch him in Ireland next month when he speaks at the fourth annual seminar hosted by the Garden and Landscape Designers Association. It will be held on February 12th in the Industry Centre, UCD, Belfield. It offers a menu of international bigwigs of remarkable stature.
Designer Shiro Nakane from Kyoto will also be there. He is the creator of many traditional Japanese gardens and natural landscape gardens in Japan, Australia and Europe, as well as the Jimmy Carter Presidential Center Japanese Garden in Atlanta, Georgia, and the Museum of Fine Arts Japanese Gardens in Boston.
As the cool and contemplative lines of Japanese gardens are becoming more popular in the west today (and tailor-made for tiny urban spaces), it's high time we had a visit from an expert who will explain that a naff concrete lantern, a plot of lumpy gravel and a slap of red paint do not constitute a Japanese garden.
Britain's soft and romantic voice of gardening, Dan Pearson, will also be heard at the seminar. His work is refreshingly iconoclastic, exuberant and bold. His Essential Garden Book, written with Terence Conran and published in 1998, was one of the better gardening volumes of the last decade.
Lastly, as is traditional in the seminar, the last speaker will be an Irish one. This year it is the turn of horticulturist and landscape architect Karen Foley, who lectures at UCD and is the secretary of the Irish Landscape Institute.
And alas, as is also traditional, tickets are severely limited. Repeated searches for a larger venue than the 250-seater lecture theatre at UCD have been fruitless, so if you want to attend, book immediately.
Tickets for the seminar cost £65 (£55 for GLDA members) and include lunch and refreshments. Contact Koraley Northen, GLDA, 73 Deer Park Road, Mount Merrion, Co Dublin. Tel: 01-2781824, fax: 01-2835724. Phone first to check availability.
Jane Powers is at jpowers@irish-times.ie