Horne aims to raise £1800 for the RHS initiative.
He said: “The benefits for young people of gardening at school are so wide ranging - from learning where their food comes from right through to improvements in health and wellbeing.
“Every school should in some way integrate gardening into daily school life right through to the end of secondary education because we also need to inspire more young people to choose a career in horticulture.
“I still remember the look of joy and excitement on the faces of pupils at a South London school I visited over ten years ago when they were showing me around their garden.
“They were so proud to reveal the shoots that had sprouted up from the ground where they’d sown a few seeds a few weeks before – one boy said the ability to create life in this little patch of soil made him feel like a magician!
“I thought at the time how much better this was for children than being sat in front of a screen and have since championed school gardening at every opportunity.”
You can support his run and the Campaign for School Gardening by visiting https://uk.virginmoneygiving.