Mr Johnson has a strong affinity with the region.

He has spent many hours rock climbing and bushwalking in the Grampians and at Mt Arapiles - usually with good friend Brendan Stemp.

Mr Stemp designed and built a seven-metre ladder for Mr Johnson's ambitious entry in the world-famous flower show.

The McKenzie Creek wood artist first met Mr Johnson at school.

Mr Stemp was settling into his role as a new teacher at Caulfield Grammar School when he was approached by a year 10 student.

"I heard he liked rock climbing, so I went and introduced myself," Mr Johnson said. "From that initial meeting we became inseparable."

Mr Johnson said his many visits to the Wimmera were reflected in his Chelsea entry.

"We built a Grampians-inspired gorge on the side of the Thames ," he said. "When I met the Queen I told her about the Grampians."

Mr Johnson discussed his Chelsea garden  - which was unanimously judged best-in-show in 2013 - at an event hosted by Wimmera Catchment Management Authority on Friday night.

He said it was a great opportunity to visit Mr Stemp and his wife, Penny.

Mr Johnson was accompanied by his wife, Sarah, and their two sons, Will, 2, and Angus, seven months.

"I love it up here," he said. "I don't get up as often as I want to - I'd love to find a little property in the Grampians one day."

Mr Johnson said he paid tribute to Mr Stemp in a new book about his Chelsea experience.