It’s cold for most of the year in North Dakota, so I’ve gotten familiar with growing seedlings under grow lights before Memorial Day. I didn’t realize you could keep on letting them grow. Green Sense Farms in Portage, Indiana, have used the unique properties of the LED to grow Herbs and Lettuce indoors. LED lighting can tuned to the very frequencies of light that plants love. The efficiency of Solid State lighting allows stacks of plants to be grown in warehouses. The advantages are climate control, nutrient control, water control, pest control, and 20–25 harvests per year depending on the crop.
I’ve did some research on the topic when I was building my own T8 Fluorescent fixtures. I used 6500K lamps and the seedlings grew fast and the fixtures used 40% less energy than with T12 grow lamps. I would love to test some of Sylvania’s LED ribbon strips in these more exotic color temperatures. (almost purple light) In the meantime, check out this article at LEDsMagazine.com for more information on the Green Sense Farms or this article on Broccolicity.com.