Microgreens Yield Data Trial: Seed Density & Yield per Tray for 29 Varieties
Background
Customers ask us all sorts of things about microgreens, from color and size to growth speed and flavor, but some of the hardest questions to answer are "How much seed should I sow, and how much will I harvest?" The Hensley's team set up a microgreens yield trial to answer exactly those questions.
Lots of factors affect microgreen yield. The two biggest are seeding density and how big the plants are when you cut them (days to harvest). Even small changes in either can change the yield. Add natural versus supplemental light, indoor versus greenhouse growing, the time of year, and differences in equipment and supplies, and it's clear that one grower's yield numbers won't carry over exactly to another grower's system.
With so many variables, we decided to share as much detail as we could about how the trial was run and what we measured.
Materials & Methods
Harvesting Mild Micro Mix
Our micro mixes are blends chosen to be easy to grow and to give tasty, clean, colorful and even stands.
The trial ran in a greenhouse in the fall, timed to finish before the days became too short and cold.
In the final week we added heat to keep nights above freezing.
We picked about 30 popular microgreens and sowed each one at least three times to see, among other things, how day length affected days to harvest and how much seed was needed for a given yield.
We filled standard 1020 flats with germination mix and sowed by eye, weighing the seed packet before and after to know exactly how much seed went into each flat.
Each variety was cut at the first true leaf. Because this is where growing systems differ most, we photographed every variety at one of its harvests so you can compare it with the size you want; the photos are on each variety's product page. Every trialed variety is linked from both the seeding rate and average yield chart and the raw data spreadsheet, described below.
Summary of Results
Raw data (XLS)
Download this spreadsheet and use it as a template to record your own trials and growing conditions.
Comparison Chart of Averages + Table of Raw Data
For every variety we report:
- Seeding density
- Yield per tray
- Days to harvest
We present the results two ways: as averages and as raw data.
- Averages. If you just want a rough yield estimate, we list averages in our Microgreens yield trial • chart of average yield per tray and seeding rate (PDF).
- Raw. For a closer look at the numbers, the full details are in our Microgreens yield trial • raw data table (XLS).
A few interesting findings in the raw data aren't reflected in the averages chart; we cover them below.
Discussion
Harvesting 'Gem' Marigold
Yield went up noticeably when we let this variety grow a day or two past its first true leaves, until the second set began to appear, before cutting.
Most of the results were what we expected.
- Many brassicas, such as Broccoli, 'Red Russian' Kale, 'Rosie' Pac Choi, and the Mild Micro Mix gave similar yields per flat.
- 'Britton' Shiso, which has bigger seed than most herbs, was sown at about the same rate as a brassica.
- The basil microgreen varieties were all sown at about the same rate but yielded different amounts, largely because their stem lengths differ, and the purple basils took much longer to be ready.
A few results did surprise us.
- Some, such as Purple Kohlrabi, took much longer than expected to form a first true leaf.
- Others, like 'Gem' Marigold, formed them quickly, but waiting an extra day or two before cutting, until just before the second set of true leaves appeared, raised the yield a great deal.
- 'Garnet Red' Amaranth is very small, so wait for the second true leaf, especially if you sow as thickly as we did. Our flats seemed to have a slower-growing lower layer, so we waited a few extra days to let those plants catch up.
Conclusion
Treat this trial's numbers as a starting point. The averages give you rough figures, and the raw data sheet is a template for your own testing. Try some of these rates and see how they work for you. Want bigger plants? Sow a little less and wait a few more days. Want to cut at the cotyledon stage? Sow more thickly and harvest sooner. Either way, give plants good airflow and the right temperatures.
One big lesson from the trial is how much good notes matter. To repeat or change a result, you need a clear record of what you did. Feel free to use our spreadsheet as a template: decide what to track and add a comments column for anything interesting along the way. Over time patterns will show up that help you fine-tune and run a more profitable operation.
Learn More
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Growing Information
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Variety Selection
