FINN and Nicki Spicer's achieivement in transforming two derelict barns and a nettle-choked concrete farmyard into a stunning wildlife oasis will be revealed on TV tonight.

Their “magical riverside garden”, complete with beehives and mini-vineyard that hundreds of people visit every year, is a 15-minute walk from Malmesbury.

Now it has won the seal of approval of Alan Titchmarsh, who has chosen it as one of his favourite back gardens in a programme being screened tonight.

The couple’s 3.5 acre rural retreat, which teems with wildlife and plants, is one of 30 that the broadcaster shortlisted from 600 nominations for in his three-part, prime time ITV series Britain’s Best Back Gardens.

Mrs Spicer, 53, said: “We love our garden and we unashamedly nominated it for this programme.

"Obviously we were delighted when Alan Titchmarsh chose us, especially as there were so many nominations.”

Located at Cowbridge on the Swindon Road, River Barn is a magnificent labour of love that has seen the couple pour their heart and soul into realising a dream.

For many years they lived in Bristol where Mr Spicer, 42, works as a senior philosophy lecturer at the city’s university.

But they had always wanted to live in the country and set about finding “a place with some land which we could do up” that was also roughly within cycling distance of Bristol.

In 2006 they found and bought River Barn that was formerly part of an arty 1910 'model farm'. The two barns they had acquired still contained animal pens and feeders.

Mrs Spicer said: “There was no water or electricity and certainly no garden. We used to come here during the weekends, fry sausages on a gas stove and have picnics.”

While converting the larger barn as a home they lived in a twin-unit caravan on the site.

“We spent two winters in that caravan. It was absolutely freezing,” she recalled.

In true Channel 4 Grand Designs tradition they project managed the conversion and did much of the work themselves.

The couple painstakingly created their wildlife-rich haven from a brick and concrete surface while also overcoming problems with creeping thistle, docks, couch grass and nettles.

They even taught themselves to use diggers and drove dumper trucks after importing tons of high quality top soil.

Their self-designed “back garden” today includes an arboretum, wildflower areas and a wildlife pond.

Mrs Spicer said: “We keep bees, we produce our own wine and we grow vegetables. I think one of the reasons Alan Titchmarsh chose us was also because we go that extra mile to encourage wildlife.”

The garden now opens to the public every year between May and September on Fridays, Sundays and Mondays. Visitors leave donations in an honesty box which has so far seen the couple raise £6,000 for charity.

They have installed a kitchen in the smaller barn enabling visitors to brew themselves a cuppa.

Britain's Best Back Gardens is screened by ITV today at 8pm.

Further information on the garden can be found at www.riverbarn.org.uk