Indoor Lettuce with Red LEDs!

Red LEDs and Lettuce seeds


I read an article in 2005 about the Japanese growing lettuce indoors under pure red LED light. Ever since then I’ve had in the back of my mind that I’d sort of like to try it one day. My wife actually does grow a variety of herbs and vegetables in a plot in our backyard. Watching her enjoy her successes finally pushed me over the edge this year to actually attempt indoor lettuce.

So just today my baggie of 1000 LEDs came in. They are spec’ed at 8000mcd 10deg and altogether should put out about 190 Lumens. However, they are super-cheapo (2.5 cents/unit) so actual output may vary quite a bits.

I’m going to figure out what the average voltage drop is on the LEDs and then design a 4″x4″ series parallel PCB circuit that where the LEDs drop as close to my power supply voltage as I can get them. Then I can mass produce the circuits, put them above my 18″x26″ bucket of dirt and start planting seeds!