The Growth Stage is Simple
Here Is What You Need to Check Each Day
Are/Were the Lights On?
Be sure the timer or whatever method you are using is working and the lights are on 12 to 16 hours per days. Sometimes we set up timer wrong (all the time for me) and they miss a day or two. Once you have your timer down pat this shouldn’t be a worry.
Are the Tops of the Microgreens Near the Lights? Why Distance Matters.
Not usually a problem with shop lights, but if you have grow lights or some other more powerful lighting system it is a good idea to make sure you have some distance between the tops of the microgreens and the lights.
Too much light can cause the leaves of microgreens to grow very small. We want leaf volume and mass.
Plants can only use so much light per day based on other factors like moisture and nutrients. The leaves are solar collectors and growing large leaves require energy. The plants only goal is to flower, reproduce, and make seed. Plants will not grow bigger leaves unless they need to collect more light (but see below). If they have competition for light, they will grow longer stems than leaves.
This plant physiology is important for growers. The majority of nutrients in microgreens is in the leaves, some minerals are more dense in the stems, but for the most part we want leaves. I have research papers linked to these studies in other Home Microgreen Courses.
The point is, we want to optimize the distance between the light source and the leaves for best leaf growth.
Too many seeds in a tray will cause competition and more stems. Too few seeds in a tray and we waste grow media for little product.
Too close to powerful light we get less leaves and less nutrients is drawn from the soil and the plants don’t store as much because light has been plentiful.
Too far from light, we get more stem than leaf, and less nutrition in the plants as they use light to store energy (nutrients). Less light causes plants to use more energy to grow and store less because extra energy isn’t available to store nutrients.
We want a plant to get plenty of light from all angles (creates less competition – more on this below) but still have to work to get some so they store more energy to use on a rainy day if you will.
That is a long way of saying keep your leaves between 3 to 4 inches from the lights after day one for optimal growth.
Does the Tray Need Water?
We don’t want to put our plants on a watering schedule. There are too many factors that can change and mess up the schedule.
We water when the microgreen tray weighs the same as the day we took it out of blackout.
By this I don’t mean put it on a scale. Judge the relative weight by hand. Coco coir and peat moss hold a lot of water. You can easily tell a dry tray from a tray that has moisture.
If a tray is heavy, put it back under the lights. If it is light, water it as discussed in the article linked in the previous lesson.
Those are the questions you need to answer each day your microgreens are growing.
More On Microgreen Competition and Why Lights are Better Than Window Sills
I like growing microgreens under lights much better than window sills for the reason of competition.
Yes, sunlight is the best light to use if it shines over all of the tray all day long.
But very few of us have window boxes or windows in positions to give a tray of microgreens abundant light on all sides of the tray. If you do, you are luck. Most of use have low light conditions or low angle light most of the day.
What the low light or low angle light does is give one side of the tray all the light it needs (yet it still grows toward the light) and the other side is fighting for more light.
What does this do?
It cause competition for light and stem elongation. More stem, less nutrients. Plants striving to reach light are using energy to grow toward it and not storing the energy. Stored plant energy is what we call phytonutrients or more simply nutrients.
That is why I like to use light bars.
A Tip for Commercial Growers
I write for people that want to grow microgreens for their own use. I am often surprised how many people that want to grow microgreens for commercial sale read and ask me questions.
That is all good. I’ll help where I can and of course sell them seed.
But a bit of advice when it comes to watering.
As a business you want to reduce costs. Watering microgreens is costly in terms of labor and even figuring out if a tray of microgreens needs water. So the best growing advice I can give to those that have a lot of microgreen trays growing is to keep your growing room conditions the same day in and day out for 356 days a year.
Keeping the room and hence the growing conditions the same makes scheduling watering, germination, growing time, all the more similar.
The more things are the same the easier it is to plan and work with your microgreens.
