We have been growing microgreens for a few years now and are in to our 3rd growing season for our Friends & Family Microgreens Club. We have been using T5 and T8* Fluorescent lights since the beginning, but the old T8’s are only used in a pinch. Seeing as we have changed pretty well all of our home lights to LED’s now, we thought we better start looking into changing out the lighting we use to grow our microgreens as well.
I belong to a microgreen growers group on Facebook and this question comes up over and over again. What type of lighting should I use for growing microgreens? I’m sure the group admins pull their hair out every time it gets asked…
As with anything, there are many different answers to this, based on several parameters. What is the budget? What level of grower are you – Personal use only, Growing Club, Start-up Entrepreneur, Large-scale Commercial Grower or something in-between.
As Growing Club members, we need to keep our budget to a minimum, as we are not a profit centre. Because of this, we started looking at LED tape / strip lights, which come in a roll and run on low-voltage. There are mixed reviews on these lights, with concerns of safety, quality and growth of plants on one side and loving the low power consumption and ease of setting up on the other.
Because of this we popped into our local LED lighting shop to see what they might offer. Canadian Wholesale Lighting supplied us with 2 different versions of LED grow lights: The tape or strip light I was thinking of, along with a package of 5 – T5 LED Tube fixtures.
What did we compare?
Ease of use
Quality of Microgreens, including:
Visual – Colour / Growth / Volume
Ease of use / Energy use
The TopLED Strip Light comes with cord / transformer and mounting brackets, but has no in-line switch. This means you would have to use a power bar as switch, as we have done, but if not using that growing shelf one growing cycle, you have to unplug the light. Not a big deal, but a little less convenient.
As we were just doing a test, we used cable ties to hold it on to wood hangers. This will have reduced the efficiency a bit, as strip curled around each end. In proper install, we would cut to length and attach with cord connectors. Light is a Red / Blue at 4 – 1 ratio. 1 – LED Strip light tested at 38 watts
The T5 LED Series Tube fixtures are boxed as a set of five 280mm x 10mm LED strip lights built in to reflective tubes, with a power cord / transformer / switch, connection cords which allow for one power cord to run a series of fixtures and brackets. Very easy set-up. The light is very hard on eyes, so we mounted them on lowest grow shelf. If you were using this style in larger install, I would recommend wearing UV eye protection. 5 – LED T5 Tubes tested at 27 watts
Our existing 60cm / 2 ft. Sun Blaster T5 Fluorescent lights are in their 3rd season. They also came with power-cord / switch, built-in ballast, connection cords which allow for one power cord to run a series of fixtures and brackets. Tubes can be replaced as needed. 4 – T5 Fluorescents tested at 84 watts total.
Quality of Microgreens
Now to the part you have probably been waiting for. How did the microgreens grow under the 3 different lights?
We grew three trays of each, making sure they were all given the exact same conditions. All were grown in 10 x 20 trays (standard greenhouse tray size), using certified organic ProMix container mix.
The grow room was kept at a 20 C / 70 F temperature (we keep it cooler then some growers as we work on a 2 week cycle). We grew Sunflowers and a Brassica mix. All trays were put under light on day 5, which includes a day for Sunflowers to be soaked before planting.
During the first cycle, the approximate height from top of soil to bottom of lights were as follows.
LED Strip – 27 cm / 10.5 inches
LED Tube – 24 cm / 9.5 inches
T5 Fluorescent – 22 cm / 8.5 inches (our standard height for these)
During the second cycle, we lowered the LED’s hoping to get better results
LED Strip – 18 cm / 7 inches
LED Tube – 14 cm / 5.5 inches
T5 Fluorescent – 22 cm / 8.5 inches
How did they grow?
You will see below, that there is a considerable difference in volume and density of the crops. The two types of LED lights had quite different success with each variety of Microgreens, while the T5 Fluorescents remained more consistent.
We did a taste test at end of second cycle. A very experienced tasting team, which included two family members and myself 😉 We did a simple 1st, 2nd & 3rd rating system. The results are as follows…
LED Strip light – Nice taste, good water content
T5 Fluorescents – Not a lot of difference to above, just a hair behind
LED T5 Tubes – Very bitter. We used in a smoothie.
LED T5 Tubes – Nice taste, good water content
T5 Fluorescents – Not a lot of difference to above, just a hair behind
LED Strip – Limp. No appeal
It seems that the different Microgreen varieties fared differently with the different lights. All I can really say is that you will have to try out which Microgreens grow well under your lighting. The big difference for most of us will be the cost to buy and cost to run.
The LED Stip lights should be the least costly to buy, as you can easily take one 5m / 16.4 ft strip and cover a 4 ft. shelf. The LED T5 Tubes used the least amount of power, but I don’t really think that the five tube package covered all the plants on 4 foot shelf that well.
The T5 Fluorescents used considerably more wattage, but are quite consistent in growing a good crop. If you are growing a few trays for yourself, the overall cost wouldn’t be that much. If growing on a larger scale, that cost would add up quickly.
We definitely would need more time to really make a proper conclusion.
*We didn’t use one of our old 4ft T8 Fluorescents as part of this test, but just for fun, its power was rated at 54 watts for a two tube fixture.
Watch for the results of our lighting test, which will come out in about a week! Over the last month, we have been testing out 2 types of LED grow lights. We will be comparing them to each other and to our existing T5 Fluorescents. Thank you to Canadian Wholesale Lighting for asking us to try these out!
We’ve just recently started playing around with microgreens for our family. Taking two old window blind displays that are best kept out of landfill, I reconfigured them a bit to line up the horizontal supports to allow for continuous shelves across both units. The light fixture that was previously hanging vertically inside one of the units makes great lighting for the top shelf.
We also picked up a few grow-light units that were on clearance at a local indoor gardening shop for the middle. These use very little power, but as you can see below, the plants love them! We still have a couple of 3 foot fixtures sitting in shop that will work once we expand to using bottom section of displays. The plastic panels that used to sit in behind the display blinds were handy as shelf covers (makes easy cleaning) and light reflectors.
This little storage room in our shop is heated with a small oil-filled heater each year already, so there will be no additional cost to keep the plants happy. We keep the heat very low and will see how happy the micro greens are once winter really sets in. About a week before this post, we were down to -4 C overnight and it was still comfortable in room.
Total cost to get going was only about $80.00 + cost of seeds. We decided to buy larger quantities. The two below we bought 10 kgs. of each. A little costly up front, but will save a lot over winter and spring. From what I can read, micro greens have an average 4 – 5 times the nutrients as their mature counterparts. There was a study at the University of Maryland that tested the claims on nutrition and found some exciting results. Here is the short version from WebMD.
We bought our seeds in bulk from a Canadian seed supplier that sells only organic, non-GMO seeds. Here is part of our first indoor crop!
If anyone else is experimenting with microgreens, please let us know. We are thinking of starting a local ‘MicroGreens Club’ next year if all goes well, where we could have affordable monthly subscriptions. Let us know if there is anything along those lines in your area.