Veteran actor Colin Firth finds the younger lot of his new film, The Secret Garden, astonishing. Along with the legendary Julie Walters, Firth is surrounded by a young cast including Dixie Egerickx, Amir Wilson and Edan Hayhurst.

"I find Dixie, Amir and Edan astonishing! From rehearsals onwards, it's actually quite chastening, you know, you come in thinking you're the old statesman and the old pro, and realising you have got a thing or two to learn," said Firth.

"Technically they are extraordinary, they are indefatigable, they always work perfect, and I am the one who is getting confused and missing my mark and all that sort of things, they put us all to shame and they are an absolute delight to have around," added the Oscar winner.

Based on Frances Hodgson Burnett's classic novel of the same name, The Secret Garden has found numerous successful adaptations into films, plays, four television series, and a Broadway musical.

"The optimism of this story is explosive and it's one of the reasons it's so enduring," said Firth, about the film, to be released by PVR Pictures in India on January 8.