How many people would give up a successful business, built up over 35 years, to follow their conscience? For Robert Longstaff, his latest venture is the result of long-held environmental beliefs.

Mr Longstaff has run down his business, Oxford Garden Products, which makes laser-cut wooden puzzles and garden screens, so that he can focus on his passion for local food, educating people about the benefits of organic gardening.

His new venture — called, rather confusingly, The Oxford Garden Project — aims to be commercially sustainable, but will be non-profit making.

At 57, he is looking for someone to take on his business, but he hopes to put his experience to good use.

His concern for the environment began in the 1960s, when he and his wife Yvonne worked for the Ministry of Agriculture.

He explained: “I spent years looking at the effect of agriculture on wildlife when we were using things like organo-chlorides, which have now been banned.

"We started growing things for ourselves while we were building up the business. We had our house and workshops and for some years we have been receiving visits from groups and schools.

“In fact, we have had school visits here in Longworth for more than 20 years. We were ahead of the curve, doing something that has become more and more popular.

“So now we have started giving talks, demonstrations and practical courses on gardening as well. It is sustainable and low-impact, which means largely organic.

“We are looking to move on, and go full-time into education and training.”

His garden gradually increased over the years, and he started doing talks for the Coventry-based Garden Organic (formerly the Henry Doubleday Research Organisation), the UK’s biggest charity working in this sector.

Both he and his wife Yvonne are 'master composters' for Oxfordshire, running courses and giving talks and demonstrations and they have worked with organisations such as Wrap (Waste Resources Action Plan) and the Love Food, Hate Waste campaign.

He is also a 'seed guardian' for Garden Organic’s Heritage Seed Library, testing seeds handed down from generation to generation, which suit local conditions better than modern varieties.

"In Oxfordshire, we have sandy soils as well as clay, and we have always had diversity. Before the Second World War, you would grow something, and if it worked, you would save the seeds and use them. It meant that you grew crops which suited the soil conditions.

“Now, the only seeds you can buy are those that do best in commercial growing. They are not necessarily best for the garden.”

He sees the venture as an organic development of his business, which aimed to keep alive lost skills such as woodworking and corn dolly making.

He tries to lure novice gardeners away from the easy option of driving to a garden centre to buy plants, and then being disappointed when they die.

"We garden for the soil. As long as we look after the soil, the plants know what to do,” he said.

Mr Longstaff believes people do not need acres of land to grow their own food, nor do they need hours of spare time.

"Most gardeners only have a small plot, but if you get together with your neighbours, you can set up community allotments.

“If you just have a windowsill, there is something that you can do. You are not going to be self-sufficient, but once you taste what you have grown, you get hooked really quickly.”

Now he needs funding to keep the project going and is looking for sponsors and money to subsidise courses, as well as businesses to lend equipment such as polytunnels, with courses teaching people how to use the products.

“The other thing we would like is more land. Already we are limited in what we can do. But we don't want to grow too big. It is intended as a demonstration of what you can do, and most people don't have acres of land, but they can still grow their own food.”

As well as tutored volunteer schemes and mentoring, his plans include rainwater harvesting, composting toilets and solar power produced from the roofs of barns.

So far he has no regrets about letting his business run down. He still fulfils Internet orders, but does no other marketing. “We have risked what we have built up for the last 30 years by doing this. But I really feel it is the right time.”

He added: "We have made a conscious decision to give up our very successful business to give something back while we can.

“A lot of people will think that we are mad and they're probably right. We have a long way to go, but we have been doing this for decades and we know the pitfalls.”

Name: Oxford Garden Project

Established: 2009 Founders: Robert and Yvonne Longstaff

Contact: 01865 820206 Web: www.theogp.org