Four years ago, a teenager with dreams of becoming a doctor came up with a simple idea: a beautiful garden for patients with spinal injuries - a place of escape, a sanctuary where they could rest and enjoy peace and quiet away from the wards.

Tragically, Horatio Chapple never lived to see the idea happen as, in August 2011 when he was just 17 years old, he was killed by a polar bear while on an expedition to Svalbard, a Norwegian archipelago in the Arctic.

Partly as a way of remembering Horatio and partly to make his ambition come true, the young man's family went ahead and raised the money to make the garden a reality and it opened in Salisbury three years ago. Now the idea is coming to Glasgow.

The new garden will be created in and around the central courtyard of the Scottish Spinal Injuries Unit at the South Glasgow University Hospital. At the moment, the courtyard has seen better days - there's some tired old garden furniture and a few potted plants on a sea of concrete - but in 18 months time it will be transformed into a beautiful green place based around a pond and an avenue of apple trees.

Some of the £400,000 total cost has already been raised but Horatio's mother has just launched the campaign to find the rest. Dr Chapple used to be a GP where the family live in Wiltshire, but now dedicates herself full-time to Horatio's Garden, the charity she established in her son's memory.

Speaking in the courtyard at Glasgow, she said making Horatio's vision happen was the family's first thought after his death. "It was my husband David's first thought - even on the day Horatio was killed, David said this is what we should do," she said. "And that came from the heart - it was what we had all been talking about before Horatio went away."

The first Horatio's Garden was duly created three years ago at the Spinal Treatment Centre in Salisbury, where Horatio had been a volunteer and his father was a consultant. "Initially, it was an outpouring after Horatio had been killed," says Dr Chapple. "We set up a charity, our friends became involved and then people who didn't even know us. They were moved by what had happened and wanted to contribute."

The garden in Salisbury contains little reflections of Horatio and his interests - there is water because he was a keen swimmer, for instance and there are apple trees because he loved the fruit - and the same will happen in Glasgow. "There have to be apple trees because that was an essential part of him," she says. "That was his big thing."

But she says the main emphasis is the idea of providing a beautiful place for the patients. "Day to day, you can see how a garden affects people and improves lives for patients - it's simple but a vital concept." It will also be completely accessible for wheelchairs so patients can come out on their own to seek some peace and quiet from the busy wards if they want to.

For Dr Chapple herself, building the garden is also focus for her. "It's really important for me," she says. "Horatio in his life - I'm sure he would have become a doctor - he was absolutely set on that and it was going to happen.

"But he was also going to do things - he would have had a big influence on people whatever he did. And I suppose this is a way of us doing that with him, and for him. It means that his life has a legacy and continues to have an impact."

The plan now is to raise the money by the end of the year, which people can help do through the website www.horatiosgarden.org.uk/donate/ and then start work in the Spring, with the Glasgow garden opening in September next year.

One of the patrons of Horatio's Garden is Melanie Reid, the writer and former Herald journalist, who is convinced the garden will have a profound effect at the spinal unit.

"I believe that Horatio's Garden will contribute enormously to the wellbeing of Scottish spinal patients," she said. "It will be an important and beautiful creation."