Passengers flying into, or out of, the Lansing airport in the dark might notice a pink glow coming from the south side of the Michigan State University campus. The high pressure sodium (HPS) lights in the teaching greenhouses have been mostly replaced with LED lighting modules.

Why pink, and not bright white? It’s all about the usable light spectrum that plants need. Plants actually do best with the red and blue light, which appears pink when mixed. Plants reflect green light waves, which is why plants are green. MSU has purchased green-lensed glasses to counter the effects of the pinkish light on eyes. With the green “sunglasses,” things appear normal under the new lights. Reportedly, the electricity usage will be reduced by up to 50% compared to the old fixtures. The old fixtures also cast quite a large shadow over the plants during the day. The new LED’s are very narrow and barely noticeable above the benches.

Dr. Kristin Getter and Dr. Roberto Lopez were instrumental in pursuing this new technology
for the teaching greenhouses. In the two houses that Dr. Lopez will be using for his class, the HPS lights were kept in half of each house so he will be able to demonstrate the effects of light type on plant growth to his students.

So, the next time you’re flying over campus, just note that the pink glow is the newest in
lighting technology and impress your fellow passengers.