Lighting up our Lettuce

Despite being an indoor farm, we still have to provide our greens with just as much light as they would receive outdoors. We do this by providing supplemental lighting in the form of electrical lamps. 

These days, indoor growers have an increasing variety of different lighting options to help their crops grow optimally. In a previous article, we discussed the use of red and blue LED fixtures, which are known for their energy efficiency. Since expanding our farm, we have branched out to using Metal-halide lamps as well.

Metal-halide lamps are commonly found illuminating baseball fields and parking lots because they are great at producing extremely intense white light that covers a wide area. They do this by igniting a mix of gases within the bulb, which produces enough heat to create plasma. This generates a lot of heat (some say up to 2000 degrees Fahrenheit!) and increasingly bright light that takes a while to reach its full intensity.

The benefits of using Metal-halide lamps for growing crops is that they cover a wider area (e.g., we use 1 Metal-halide lamp to cover the same area as 4 of our LED lamps!) and also produce more intense light that can reach all the way down to the bottom-most leaves of most plants. The trade-off is a light that can be expensive to run (compared to LED), requires routine bulb changes, and runs very hot. 

Nevertheless, we are happy to have another interesting and unique way to grow fresh greens for our food bank clients and our crops don’t seem to mind the difference between our Metal-halide bulbs and LED units much at all! 


If you would like to learn more about how we grow or see the difference between the lights yourself, sign up for one of our monthly tours here.