Imagine a million acres of new nature reserves, scattered like countless pieces of a green mosaic all over Britain, and costing next to nothing to create.

We are not talking special skills or complicated management. Anyone can build one of these wildlife havens. All you need is a garden. Entry level qualification is the ability to do nothing at all.

That’s not quite the fantasy ambition it sounds, when you listen to the man who is promoting it. Jimmy Doherty built a successful visitor attraction farm from nothing, and made a TV series out of it. Oh, and he’s chipped from the same background block as one of the most inspirational of our young TV stars, Jamie Oliver – the pair have known each other since nursery.

The idea has come from Jordans, one of the largest producers of natural and organic breakfast cereal products in the UK. The company wants  to adapt a programme already working successfully on the farms of their grain suppliers. The farmers are paid a premium price to leave one tenth of their land uncultivated and given over to nature. There are clear signs that it’s good for wildlife.

Now Jordans has asked Jimmy Doherty, who told the story of how he set up a farm dedicated to rare breeds and conservation in the TV programmes Jimmy’s Farm, to spearhead a campaign to ask us to do the same.

You simply designate 10% of  your plot, however extensive or tiny, and let nature take its course there. If you want to give wildlife an extra lure, you could make a pond, put up bird boxes, create a compost heap, even install hibernation boxes for lacewings.

The benefits could be potentially huge to our increasingly threatened wild creatures, says Jimmy. We should think of all those little wild patches of ground as refreshment and resuscitation points where wildlife can drop in, or stay put if it chooses. “We could be talking as many as 1 million acres, so many little habitats making the largest nature reserve in Britain.”

Jimmy Doherty is well-placed to ask us to make this small sacrifice.  He applies the 10% rule on his own 33 acre farm, just south of Ipswich in Suffolk. Since he acquired the rundown estate 10 years ago, and took a slab of marginal land between a river and wood out of  production, he’s seen wildlife gradually move back in.

The big push towards conservation on agricultural land began in the 1980s. Many farmers took up the challenge in different ways, such as cutting down on spraying, planting trees and leaving bigger margins around their fields.

The Conservation Grade farming scheme, which the farmers selling to Jordans adopt, is on a bigger and more organized scale. The principal condition in a seven-point program is committing at least 10% of the farmed area to a range of managed wildlife habitats.

“I’m trying to encourage anyone with a garden to do the same,” Jimmy said. “You don’t have to call yourself a gardener. A wildlife garden is pretty easy, because you don’t have to do a great deal.

“If you have an awkward corner and you’ve tried to plant things, but it’s not working because it’s too wet, too dry, or too shaded, this place can become your ten per cent.  You can either let it go wild or actively create some habitat in that space.

“There might be a tree. So in goes a bird box, and a bird feeder. Put in a bird bath. Put your compost heap there. Aerate it by mixing in leaves and some bulky matter. That bring in all sorts of different worms   And it’s a fantastic habitat for invertebrates. You might even get grass snakes laying their eggs in rotting vegetation.

“Build yourself a log pile. You can buy logs from any service station. Pour water on them.  When they are damp you get a lot more insects  in there, breaking down the cellulose.  All of a sudden you have a fantastic habitat for  beetles and other creatures and you are building up the base level of the food chain.”

This has been a bad year for British wildlife. Greenfinches and chaffinches are in decline, hit by a virus. Last month (September 2011) we heard about a big fall in hedgehog numbers.  Jimmy isn’t arguing that action in our gardens is going to bring species numbers bouncing back. However, he says, doing those simple things will help re-establish and build up the base level of the food chain. And that will benefit birds and other garden creatures.

Studies on farms in the Conservation Grade farming scheme have shown positive results. There have been increases of 41% in bird numbers (including a 1400% increase in tree sparrows on one farm); 13.5% increase in bird species; 22% increase in butterfly species; and an overall 25% increase in total species on farms.

Under Conservation Grade rules, farmers may use some conventional agricultural fertilizers, pesticides, and herbicides. But they must apply them so they do not adversely affect the health of the wildlife on farms.

Jimmy is admirably suited to lead a campaign  for another reason. As well as being a successful farmer himself, he is an exact contemporary  and good friend of one of our most inspirational  young TV stars, Jamie Oliver. The pair have known each other since nursery school. They went to the same junior school then secondary school. “We’re still in regular touch, bouncing ideas around, and sending each other texts.”

After university, where he gained a Ph.D. in entomology, Jimmy decided he didn’t want to do “number-crunching” in a laboratory. Instead, ten years ago, he rented a derelict farm just south of Ipswich.  “I started with some rare breed pigs,  went to six farmers’ markets a week, and slowly built it up.” It was Jamie Oliver who made him a loan in his early years to help him get started.

Jimmy’s Farm, which has 30 people working on it full-time, has big numbers of rare breed farm animals. (It’s open to the public.) The pigs he breeds are Essex, Saddlebacks and Gloucester Old Spots; he also keeps four different breeds of cattle, Red Poll, Highland Cross, Galloway and British White.

He runs an apprenticeship scheme for young people who want to be butchers, or gardeners or work in livestock. He’s into catering too, turning a 200-year-old-barn on the farm into a timber-framed restaurant.

Jimmy knows he isn’t exactly promoting a fresh idea, with wildlife gardens a staple feature of Saturday newspapers for many years now. “What is new is that Jordans have put  a figure on it, 10%  of your garden. This gives the campaign a structure, rather than them just saying everybody should leave a weedy patch  in  their gardens.”

And there’s another thing. A new generation who were at nursery school – just like Jimmy – in the first flush of environment consciousness in the late 1980s, are buying houses and acquiring gardens. “They need to be reminded. The environmental message has to be reinforced and repeated to them.”

Although he may not have the public profile of his very illustrious schoolmate Jamie Oliver, he’s put in the hard work and built a successful business based around animal husbandry and farming, and speaks with authority.

He now makes all his TV programs for Channel 4, with several productions in the pipeline, including a series on British woodlands, another on animal welfare and a seasonal special on the Christmas Dinner. Jimmy’s is a name to watch among the new generation of TV nature presenters.

• Jordans, formed in 1972 by brothers Bill and David, is one of the largest producers of natural and organic breakfast cereal products in the UK. The Jordans range includes Muesli, Country Crisp, Crunchy Oats, Porridge, Creations and Cereal Bars.
• http://www.jordanscereals.co.uk
• http://www.jimmysfarm.com/