But green-fingered charity workers and students have given a 38-year-old Volkswagon a makeover – and made it the centre-piece of their exhibit at Scotland’s largest gardening show.

The horticulture charity, Perennial, was offered the old car by the Lothians-based VW Club.

They had used it for fundraising events, including making it amphibious, but it was reaching the end of its life.

The charity transformed it with the help of students from Oatridge College in West Lothian, painting it bright yellow and filling it with marigolds and sunflowers. Their garden, named Perennial Petal Power, promises to be one of the quirkiest exhibits at Gardening Scotland this weekend.

Thousands of keen gardeners are set to flock to the show at Ingliston. Now in its tenth year, it will feature more than 400 exhibitors and 15 show gardens. Other highlights include the BBC Scotland Beechgrove Theatre, a craft and food fair, and gardening and cookery demonstrations.

Alex Rutherford, Perennial’s Scottish organiser, said the group was keen to use recycled materials to create a quirky exhibit and highlight its work.

The charity won the Best In Show award for its garden made from recycled junk in 2007.

She said: “This was really created to reflect the work we do. We do a lot of work with retired gardeners and horticulturalists who are often forgotten about. We give them and their families financial, social and emotional support.

“The VW was decrepit – it had done a lot of charity work but was reaching the end of its life. It was sitting in the bottom of a garden in Ratho. The students brightened it up a bit by painting it – it looks a bit like the flower power car.”

The car had been adapted by the VW Club so it could be used as a motorboat on water. It has crossed the Firth of Forth and travelled to Skye, helping raise £10,000 for arthritis research.

It has now been filled with special plant containers, with more on the roof, and was installed yesterday in the centre of Perennial’s show garden.

Ms Rutherford said one of the most difficult parts was moving the car. She said: “We took it on a trailer. It has no brakes, so we needed the students to stop it rolling down the hill.”

Agnes Stevenson, a spokeswoman for Gardening Scotland, said: “Perennial have a history of doing unusual gardens, and this year is no different.

“They do everything to an exceptionally high standard, and I imagine they’ll be in the running for a medal.”

She said this year’s show was set to be the biggest ever, with more than 30,000 people expected. The Princess Royal, who is patron of the Royal Horticultural Society, will be visiting on Friday.