Alan Titchmarsh said gardening can help people living with Alzheimer's after he featured one of the youngest people in the country to be diagnosed with dementia on his show.
The broadcaster welcomed 32-year-old Daniel Bradbury, who was diagnosed with a rare form of the disease in 2017, onto the upcoming series of Love Your Garden.
Mr Bradbury is a landscape gardener and had long dreamed of building a green space for children Lola and Jasper, and wife Jordan.
As his dementia progresses, the father of two is facing increasing difficulties with his mobility, speech and coordination, leading Titchmarsh and his team to step in and build the garden.
Titchmarsh, a long-time supporter of the Alzheimer's Society, said: "I loved working with Daniel and Jordan on this very special episode of Love Your Garden. A garden can help people living with dementia take part in physical activity and stimulate the senses and memories, all of which greatly improves their well-being.
"Dementia is one of the biggest challenges that our society faces today - by 2021 there are set to be one million people living with it.
"We knew that Daniel, as a landscape gardener, really wanted to build a garden for his family but was sadly no longer able to do so because of his condition, so we jumped at the opportunity to help."
Mr Bradbury, who got married last year, inherited dementia from his father who passed away in 1990, aged 36. There is a 50% chance that Lola and Jasper have also inherited the rare gene from Mr Bradbury.
Mrs Bradbury, 31, added: "We feel incredibly lucky to have met Alan and the team and watch Daniel's gardening dreams come true before our very eyes.
"Working with Alzheimer's Society, the team were able to make sure that the final result was able to accommodate Daniel's needs, as well as giving Lola and Jasper somewhere spectacular to play in.
"I hope others enjoy watching our little garden get such a wonderful makeover as much as we did!"
Former Ground Force presenter Titchmarsh is backing the Alzheimer's Society's Memory Walk campaign, raising vital funds to beat dementia.
The Memory Walks take place across England, Wales and Northern Ireland during September and October.
You can register for the Memory Walks at memorywalk.org.uk. The Love Your Garden episode featuring the Bradburys will air on ITV on August 27.