Murphy, who has been the club ambassador for the charity since he joined the club six years ago, was joined at the infant school by the Mayor of Solihull, Cllr Joe Tildesley.
The left-back spoke to BluesTV
about the work the Prince's Trust do.
He said: "The Prince's Trust is a great charity and I've enjoyed everything I've done here. It's something I've always been keen to do, get into charity work and help other people."
Murphy and the Mayor both cut the ribbon to officially unveil the new garden.
Vanessa Morris, Team Leader from the Prince's Trust, was delighted with the outcome and even more delighted to have Murphy and the Mayor there to unveil the project: "Its really wonderful that Blues are showing their support for the school and our team.
"It is a total transformation, its a usable and sustainable area for the children and its going to be something they can use for many years to come."