Lighting for microgreens will ultimately decide if your microgreens can grow strong. If you have weak looking microgreens, better lighting could be the answer.
How much light do microgreens need?
You need to to satisfy one of these depending on your growing environment:
- Direct Sunlight: At least 5 hours a day.
- Indirect Sunlight: At least 8 hours a day.
- Grow Light: At least 8 hours a day. Can accelerate growth if left on longer. But keep it at 12 max because all plants need some shuteye to grow properly.
You can grow your microgreens in a sunny windowsill for free energy. During the summer, this should be plenty of light. During the winter, you might find that your microgreens aren’t looking as strong as they were during the summer. If that’s the case, you might need to invest in grow lights (under very low light conditions like living in Alaska).
What happens if microgreens don’t get enough light?
All plants grow towards light so they can soak up the nutrients to grow healthy and strong. When you deprive microgreens, or any plant of light, it will continue to lengthen to find a light source.
If microgreens aren’t getting enough light, the first thing that will happen is that they will get “leggy” and tall by growing longer to find the light source.
Depriving microgreens of light during the initial germination phase is actually a great way to increase your growth of the microgreens so you get more to eat. But at a certain point, they are going to be too tall for their small root system to support and will become weak.
The rule of thumb should be to deprive microgreens until they are around an inch tall and then give them as much light as you can.
Do microgreens need grow lights?
No. Microgreens don’t need grow lights. Microgreens can grow faster and stronger because of supplementary lighting but you don’t even need a grow light, regular house lights can even do the trick in a pinch.
If you can’t satisfy the hours of lighting recommended above for direct or indirect lighting, that’s when grow lights might actually be needed and worth the investment.
I tested growing broccoli microgreens with and without a grow light. The microgreens under the grow lights did perform better in terms of rate of growth but did not seem to change the end result of the microgreens.
From my own opinion, I think a grow light is worth it only if:
- you really want to speed up the process of growth
- you have tried growing microgreens in your current environment and it’s just not happening
If you’re gonna try grow lights, which one should you get?
Kevin from Epic Gardening has an amazing article about Indoor Grow Lights which you should check out if you are having difficulty growing beautiful microgreens or want to accelerate the process from seed to mouth.
What about using the regular lights in your house?
Indoor grow lights are specifically created to produce certain wavelengths that benefit plants during growth. Normal house lights aren’t designed in that fashion but they do produce some of those wavelengths.
In the end, keeping your regular lights on is going to be expensive unless you have LED lights already installed. Because of the inefficiencies of using your regular house lights, it’s worth getting a desk grow light or something that you can mount above your microgreens.
The main takeaway is light is important but there are many ways to get your microgreens enough light. Before investing in a grow light, give your own sunlight a shot and see what comes of it.
If you have any other questions, let me know so I can update this post in the future. Thanks!