With their low energy usage, reduced heat output and the ability to control the light colour they emit, LEDs are poised to revolutionise the horticulture industry. “It’s a real luxury to eat locally grown, leafy greens in the middle of a Chicago winter,” declares Robert Colangelo, founder and CEO of Green Sense Farms. Before he launched his business in 2012, the only truly feasible way to provide fresh salads and herbs during the cold Illinois winter was to truck them thousands of miles from farms in the warmer southern US states. However, Colangelo has no ordinary farm. Inside a warehouse 40 miles south-east of Chicago, his ‘vertical farm’ contains rows of tightly packed plants, stacked from floor to ceiling. Bathed in a bluey-pink LED light, the vertical farm principally grows salads, herbs and starter crops, while also constantly experimenting with new plants. Green Sense Farms, which is in the process of building new installations and selling its technology worldwide, mostly supplies a local Whole Foods Market distribution plant, as well as nearby restaurants. Colangelo’s farm offers benefits beyond producing basil in winter. He is able to intensively grow his crops within ...