Monty Don continues his extraordinary journey with a visit to the richest and most powerful nation in the world: the United States of America. There, he meets garden guerrillas who are creating community gardens from derelict land in New York, visits a Virginian garden that reflects the birth of the nation, and finally travels west to California, to see if gardens there reflect more than the glitz of the movie industry.

Gardens:

30. LongHouse Reserve, East Hampton, NY

31. Gantry Plaza State Park, New York (designed by Tom Balsley)

32. Liz Christy Garden, Manhatten NY

33. James Van Sweden's garden at Ferry Cove, Chesapeake Bay, Maryland

34. Monticello, Charlottesville, Virginia

35. The Huntington Botanic Garden, San Marino, California

36. Lotusland, Montecito, Santa Barbara

37. Roland Emmerich's Garden, Hollywood, California

38. The Greenberg Garden, Brentwood, Los Angeles (designed by Mia Lehrer)