Nottingham-born actor George Robinson, an appeal ambassador for the project, called the garden “incredible”.
He was a patient at the spinal injuries unit for almost eight months in 2015, after suffering a severe spinal injury during a game of rugby when he was 17, which left him quadriplegic.
He said: “When you spend so much time in hospital, you’re focused on your physical rehabilitation, but as the days go by, you realise you also need that mental rehabilitation – sometimes that clinical environment isn’t the best place for that.
“You can feel separated from the world, but a garden connects you back to it.”
He added the space would give patients a “sense of purpose” by taking part in activities such as gardening.