In three hours, 135 visitors came to see Jane Baker's backyard. She is one of many who open their garden gates to the paying public. By Julia Kaminski
The little boy already had his trousers round his knees and was looking around for a suitable flower bed when his mother caught up with him. "Not here darling," she whispered, hurrying him inside to a more appropriate venue.

That was one of the consequences Alison and John Taylor had not foreseen when they took the plunge and opened their garden to the public as part of the National Gardens Scheme. They were encouraged to do so by a neighbour and keen gardener, Valerie Cravens. Before the opening, they were warned that people may try to sneak the odd cutting, but peeing in the flower- beds? Surely not.

Alison, 30, admitted to being nervous a week before the opening last weekend. "The Sunday before, I woke up with a feeling of apprehension, although the Big Day was still a week away. But on the actual day, we didn't have to do much. It's a bit like revising for an exam - you get to a point where you really can't do any more."

Most of the graft had been done in the previous six months. "We did loads of extra work," Alison said, "including brick-edging the lawn two weeks before. In the spring my pots were full of tulips and daffodils, and I had to take them out early, to put in the other plants ready for the June opening. I had to force the season a bit."

She admitted to increasing jitters as the day approached. The National Garden Scheme vetting process, by contrast, had been remarkably simple. "I thought they would ask me lots of horticultural questions," Alison said. "But they took a look at the garden and said `yes' immediately."

On the day of opening to the public, Alison was afraid she would not be able to answer all the questions, even though she had designed and planted the garden in Greenwich, south-east London, herself. Borders are planted with lilac, buddleia, hostas and varieties of clematis. One side is hedged with young silver birches, and a Mediterranean-style terrace is partly secluded by a trellis draped in honeysuckle and climbing roses. One of the biggest attractions (besides Spartacus the cat) is a tiny lion- faced fountain set into a wall. The patio is dotted with large terracotta pots brimming with margueritas and pink and purple petunias.

"People did ask some difficult questions," Alison said, "and there was one plant whose name I couldn't remember because it was quite new and I'd thrown away the information. It flowered for the first time just a few days before, and looked spectacular - blue petals with a red centre. So of course, everyone wanted to know what it was, and I couldn't tell them. Now I know - an anagallis."

John Taylor escaped that part of the nightmare by welcoming people and selling tickets - the cost of a visit was pounds 2, which covered entrance to this and a neighbouring garden. "I wasn't asked many questions, thankfully," he said. "Though someone did enquire as to where we bought our curtains. I was most worried that no one would come, or that they would all come at once towards the end. In fact, the first guy arrived early, at five to 11. I was expecting a friend, and was holding a hammer when I answered the door."

Ten doors away, Jane and Peter Baker were also opening to the public and they were equally nervous - but for different reasons. Their garden, in sharp contrast to the Taylors', is on an extremely steep slope and has been landscaped on four levels, with tall retaining walls. "I was terrified people would fall down the steps," Jane said. "I was worried they would behave badly. Most of all, I was scared there wouldn't be enough cakes.

"We were persuaded to open to the public because much of the money goes to the Cancer Relief Macmillan Fund. I actually wanted to open the house so people could view the garden from higher up, but the organisers warned me against it. They said they'd never had any trouble, but just in case... And in the end, people were absolutely lovely. Angelic."

Jane had her garden designed and planted by Anna Laine, a neighbour and garden designer, who was on hand to answer questions.

"Plants need to have impact," Anna Laine said, "and you should try to achieve a balance between leaf shape and texture and colour. You must have a contrast between delicate foliage and something bold, such as this Fatsia japonica. Jane likes things natural, as I do, so we've let things seed in the crevices of the walls."

Grey foliage such as senecio mingles with pink cistus, purple sage, lavenders, thymes, and a tall purple fennel. The lower, shady terrace has a woodland feel, with white foxgloves and forget-me-nots. White flowering clematis tumble over the walls. The top level, a secluded sun-trap, is full of pink and purple blooms - phlomis italica, lavender and roses.

Was the ordeal a success? In three hours the Bakers had 135 visitors, aged from several months to nearly 90, and at least one professional gardener. A few doors down the Taylors were also pleased with the outcome of their open day. "It was quite a social event," Alison said. "People say there's no community spirit in London, but this proves that's not true. Everyone was genuinely friendly. Neighbours and even the convent over the road offered us help."

Alison encountered one visitor who had been born a few doors away more than 80 years ago. Another woman had come to the house 30 years ago for her wedding dress fitting.

As the last satisfied visitors drifted away, an air of relief and elation settled on the hosts. Bottles of wine were opened, a large brie produced alongside fresh crusty bread. "I feel euphoric," Jane said. "We could do it again, couldn't we?"