Monty explores the extraordinary scenery of the west coast of America. In Arizona, Monty learns about cacti and marvels at the sight of them in the desert and in private gardens.

Monty Don goes south to explore gardens of early independent America and learns how the history of this part of the country is still very much evident in the places and people he meets.

Monty begins his trek in a prairie, the original American flowering wilderness, only to find much of it has disappeared. In New York, he explores vegetables being grown on the city's rooftops, visits an enthusiastic allotment community in the Bronx and learns about the history of America's most famous public green space, Central Park. In Philadelphia, Monty examines one of the country's most famous gardens and enjoys a modern version of a prairie garden.