Blue Light Special

This winter, I've experimented with using a LED light to grow greens indoors. The pots are next to the (south-facing) kitchen window, so they have got some natural light, although not that much, considering how far north we are.

The lettuce is Winter Marvel from Real Seeds (scroll down to the winter lettuce section). This variety did quite well in the garden under cover until we got greedy and ate it all!


I've read that plants need blue light for vegetative growth and red light for flowering. Since I'm growing lettuce, I tried blue light only. Some say it may be better to use a mix of red and blue or full spectrum LED. More technical information is available here.

I've noticed some leaves twisting upside down and turning their undersides to the light. It may be that the bulb is too close to the light. However, I've been harvesting leaves off these plants for weeks now and they keep growing exuberantly, regardless of which way the leaves face.

Normally I avoid eBay, but I made an exception this time and got my blue LED light from Hidden Hydro. While the bulb is quite expensive, the running costs are pretty low for this one bulb. Our energy monitor says it uses 0.09 kwh/day or 31.39/kwh a year. That means it costs £5.17/year to run the bulb 24 hours a day 365 days a year.

I'm thinking of ordering some more bulbs to make a bigger setup that I could put on top of our kitchen cabinets (space limitations!).