In the far off days when net curtains twitched, a neat front garden announced that the household was respectable.

Ham & High: Project Dirt - Lift one paving stone campaign . Annie Cartwright pictured working in her garden in Stroud Green. Picture: Nigel SuttonProject Dirt - Lift one paving stone campaign . Annie Cartwright pictured working in her garden in Stroud Green. Picture: Nigel Sutton (Image: � Nigel Sutton email pictures@nigelsuttonphotography.com)

Respectable rather than interesting – many interesting plants could not survive in smoky cities anyway – so crazy paving, red geraniums and a neat privet hedge were quite adequate.

So what has replaced that style, in the 50-plus years of freer social attitudes and better (at least less smoky) city air? Have people expressed themselves more, embracing the improved conditions and choice of plants in their front gardens?

Well, up to a point.

The range of plants visible from the street is certainly wider. The main recent growth, however, is not of interesting plants but of stone, concrete and chippings – hard surfaces are reckoned to have increased in London by 36 per cent in the last 10 years.

Everyday, people are covering up more earth, probably with the contented feeling of getting things under control, of vanquishing weeds and untidiness.

They may be unaware that more hard surfaces mean more rainwater running off into overloaded drains, and reduced habitat for life-sustaining insects.

To try to counter this trend, the campaign Lift One Paving Stone, led by North London Transition Towns, and supported by this newspaper, has come into being.

It aims to encourage the re-greening of hard-surfaced front gardens and building entrances.

The campaign got off to a good start last week, thanks to Debbie Bourne and her partner, Stephen Evans, who run the wildlife friendly gardening company, Of Butterflies and Bees.

When we arrived at the scene, Tim Wood and Andrew, who are part of Debbie’s team, had already lifted a lot of bricks and roots from Jemima Murray’s front garden in Hampstead, in readiness for the laying of wildflower turf.

Annie and Bob, Jemima’s two older children, came out to help, while three-year-old Rafe looked on, somewhat sceptical.

One environmentally sustainable aspect of this project was that Tim and Andrew had come on foot rather than in a van, bringing their tools with them. Andrew has a specially-adapted sack-truck-cum-army-kitbag for the purpose.

Our next appointment was with Sheila, an elderly resident of Spencer Rise, NW5, who had responded to the campaign’s offer to enliven her front garden.

After a brief, smiling appearance she went back inside, happy to give Stephen and Debbie free rein. Like most London streets of terraced houses, Spencer Rise has a range of front gardens, from pretty, through tidy to dreary.

First discarding an old Christmas tree, Stephen lifted a paving stone and dug into the fresh earth below.

He and Debbie quickly planted the irises, wallflowers, nasturtiums and carrots they happened to have spare – a random collection but it made the front look much better.

While they were working, a neighbour took a friendly interest.

It was her promise to spread the word to other households that soon had Debbie picturing the whole street transformed.

It must be stressed that the campaign offers encouragement to householders, rather than a free make-over service.

Our last visit was to Annie Cartwright in Blythwood Road, N4.

Annie, a community gardener for the Westway Trust, is gradually uncovering her once totally paved front and back gardens.

She had just smashed up a big concrete paver in the front and was planting verbena, aubrietia, geranium, hellebore and sedum in its place. “The soil was beautiful,” she said, “only a bit gravelly.”

Just think of how much more beautiful soil is out there, waiting to be uncovered.

If you would like to support this campaign with gifts of spare plants, they would be sure of new homes. Email debbiebourne21@gmail.com. There’s information about the campaign, with details of the related competition, at projectdirt.com/liftonepavingstone.