LONDON—In its never-ending focus on antiques—“Antiques Roadshow,” “Cash in the Attic,” “Flog It,” “Bargain Hunt,” “Sun, Sea & Bargain Spotting,” “Car Booty”—the BBC anticipates collectible finds with “20th Century Roadshow.” Host Alan Titchmarsh, well-known gardener and horticultural journalist, joins experts as they travel around Britain providing appraisals of some surprising contemporary collectibles, ranging from Pokémon cards and lava lamps to a 1960s lip-shaped love seat, Beatlemania and 1950s textiles. Evaluators range from original “Roadshow” stalwarts to new experts with blue hair and shocking wardrobes, who specialize in modern-day, not-yet-antique treasures. The series airs on BBC1 in Britain and CBC in Canada. There are no plans as of yet to broadcast in the United States. For more information, visit www.bbc.co.uk.