Additional Information & Resources
There isn’t one perfect seeding density.
However, the seed density calculators I developed will give you an excellent seeding density for any size tray.
Based on personal preference, you may add a little more or a little less seed on the trays you grow.
However, the results of my calculators will provide you with an excellent starting point. Adjust the amount as you see fit.
I have provided you with two pdf worksheet files that you can download and print.
These documents are to record your seeding trials and dial in your perfect seed density for each microgreen variety you grow. Once you have these worksheets filled out for the varieties you use most often you will not have to log back into the course until you try to grow a different microgreen.
What Affects Seeding Density?
Germination Rate
The most significant effect of seeding density is the germination rate. There are federal and state seed packaging requirements.
One of these requirements that all states require is the germination rate.
However, the germination rate must only surpass the rate stipulated on the seed packet at the time of testing.
Some seed providers are accurate with this listing, where each seed variety will have the actual rate. Other companies list all of their seeds at 85%, even if the germination rate is higher (assuming the rate was higher and not lower).
The listed packing rate can’t be used very well to adjust the seeding density because it might not be precise.
A five to ten percent difference in germination rate can cause crowding or under-seeding in microgreens. So, each lot of seed should be evaluated, and seeding rates adjusted if necessary.
A visual adjustment is all that is needed. For example, if you grow a tray that seems crowded or thin, then the next tray you plant, add or subtract a bit of weight on the scale or round or remove a few seeds from the measuring spoon.
My calculators are based on an 85% germination rate.
Growing Conditions
The amount of water, humidity, soil, temperature, airflow, light, pre-conditioning seed, and the growing method can affect how well seeds germinate. These variables can cause minor to significant effects on the germination rate of seeds.
Because all these conditions can affect how microgreens germinate and grow, I recommend keeping as many things as possible the same.
Grow in the same size trays (or use the same seeding rate using the calculators) and soil each time you grow microgreens. And roughly record the other variables, so diagnosing what makes a grow tremendous or poor is easier.
In an upcoming course, I will touch on all of these aspects of growing great trays of microgreens repeatedly and how to diagnose and solve problems if they occur.
Why Seeding Density is Important
I discuss the points why seeding density is very important to growing microgreens in the video.
Besides the nutritional value of the microgreens, we can’t forget that seeds planted too densely reduce air flow and can cause disease issues. Sow the seed to lightly, and you have wasted money by not utilizing all of the potential of the grow media.
If you want more information on the nutritional value of the stems and leaves of microgreens, the research papers are linked below.
Nutrient and Bioactive Compounds in Leaves and Stems.pdf
Nutritional and Antinutritional Values of Leaves and Stems.pdf
Nutritional Quality and Health Benefits of Microgreens.pdf
Home Microgreens Nutritional Resource
I have created a huge resource on the nutrition contained in microgreens and leafy greens. Click the button below for more information.
How I Came Up With My Seed Densities
As mentioned in the video, there was a logic I followed to develop my seeding rates. It is discussed more in the following article.
How I Calculated Seed Densities
Coming Up Next
In the next lesson, I will show you how to find the dimensions you need to use the seed density calculators.
Useful Supplies
Here are the trays, soil, scale, and measuring spoons I use in the video.
Don’t Make a Mess Tray
Home Microgreens Tray System
1010 Planting Tray
1010 Watering Tray
1020 trays – Coming Soon
Home Microgreens Potting Mix
Measuring Spoon Set
Gram Scale
