Lighting – Blue and Red Lights For Photosynthesis

Q: I read your recent reply to a question about using LED bulbs instead of fluorescent bulbs for plants in a kitchen. If I want to make a lighting system for sprouting seeds and maintaining my Meyer lemon in winter, does the same information apply?

A: If you want to build a custom setup, it helps to understand that plants use mostly red and blue light for photosynthesis. Their leaves reflect green light, which is why plants have “greenery”. A great advantage to using LED’s is that you can buy LED bulbs that emit only red or blue light. The plants won’t look quite right to your eyes but they will efficiently use the red and blue spectrum you give them. Fluorescent bulbs or tubes can not be “tuned” to plant needs so precisely.

That said, making your own blue/red LED array is complicated. You can buy LED systems from hydroponic or aquarium stores and that’s what I recommend. They’re expensive, but you’ll save on energy costs in the long run.