Manicured lawns, flashy flowers and trendy garden designs – every year we spend billions of dollars and untold hours in our quest to have the lushest yard on the block and turn the neighbours green with envy. Our never-ending hunger for the brightest blossom and the biggest tomato has created a massive, automated industry where plants are produced by the millions in factory-style grow operations. Gardening Confidential takes a behind-the-scenes look at how this most ancient of hobbies has turned into a high-tech obsession where you don't even have to get your hands dirty anymore. This special takes us on an international exploration of one of the most obsessive hobbies in human history, and discovers some surprising modern twists. From robotic lawnmowers to gardens on Mars, meet some of the most single-minded gardeners in the world and discover how gardening can get you in trouble with the law.