This strange crop has never seen the light of day ? strong light destroys the carefully contrived balance of nitrogen and phosphate inside their closed glass containers, which would prevent the plants from flowering. Instead, these designer blooms use light-emitting diodes (LEDs) as their only source of light energy.

Tokyo-based Stanley Electric, a manufacturer of lighting devices for cars, developed the cultivation technique in collaboration with Yasuhiro Mori, a researcher at Tokai University in Kanagawa, Japan. They have so far produced roses and torenias. It took the research group five years to arrive at the successful exposure levels of blue, red and green LEDs. Stanley Electric plans to put the plants, which require little space and care, on the market this spring.