How plants can be key to unlocking memories in dementia patients

Among the 12 participants, some have lost — or are beginning to lose — their short-term memory.

Others can be easily confused about where they are, get distracted, or struggle to formulate a sentence.

Over an eight-week period, the participants immerse themselves in the garden and are encouraged to smell and touch flowers, ferns and herbs, as well as learn about the flora and fauna.

"There was a lot of emotion in it – it was really wonderful."

Michael Shirley said Bronwyn, his wife of 45 years, always loved gardens.

Five years ago she was diagnosed with Alzheimer's.

"She's able to understand everything you say, but can't answer you back," Michael said.

At one of the Botanic Garden sessions, Bronwyn excitedly said, "Oh, I love that".

"It had been years since I heard a complete sentence," Michael told The Drum.