When breeder John Cho combined a black Colocasia and a glossy Colocasia, he created something shiny and new: ‘Diamond Head’. It is named after the volcanic cone on the Hawaiian island of Oahu, which makes sense because both the cone and the plant are black and lustrous. The plant’s leaves reach at least 16 inches long and 1 foot wide. ‘Diamond Head’ performs best along the edge of a pond or submerged in a water feature. If left in dry conditions, its leaf edges burn. In shade, it loses luster and appears dark green instead of purple or black. That purple-black color is what makes ‘Diamond Head’ so special, so if the light conditions in your garden don’t suit it, you might want to choose another cultivar. —Adrienne Roethling, Fine Gardening #148