Building a Simple Greenhouse Part 4- Supplemental Lighting

March 18, 2021

The amount of supplemental lighting you need will wholly depend on where your greenhouse is built and how much natural sunlight you get. Cool season crops such as lettuce, spinach and kale require 6-8 hours of light per day, so when designing your greenhouse you'll want to find an area with as much direct sunlight as possible. For those that find themselves in similar situations to ours where sunlight is limited, you will need light supplementation.

We chose to use our most powerful light, the GrowtechX660, to provide the additional light we need in our 6x8' garden.

In a normal indoor growing situation, connecting the fixture to a manual timer and programming on/off times would be sufficient, but this outdoor grow is a bit more complicated than that. Our natural sunlight hits roughly between the hours of noon and 2 PM. We'll want our light fixture on in the morning hours, off when our garden is in direct sunlight, and on again to finish the few remaining hours of the day. To achieve this we will be using our optional WIFI gateway/controller system. By connecting the gateway to our wireless router and the controller to our X Series fixture, we now have the ability to control the light intensity and on/off times via an app on any mobile device. We'll only be programming our fixture to use 60% light intensity at the start of our grow and adjust as necessary as our crops grow. We'll be programming timers so that our fixture comes on at 9am, shuts off between noon and 2pm when we have full sunlight, back on again from 2-5pm, and finally completely off from 5pm until 9am the next morning. This gives us a solid 8 hours of lighting, exactly what our spring crops need.