Johnny's Microgreens Yield Data Trial: Seed Density & Yield per Tray for 29 Varieties

Harvesting Mild Micro Mix

Our micro mixes are carefully curated combinations developed for easy production of delicious, clean, colorful, reliably uniform stands.

In early September we set up a trial in a greenhouse designed to be completed by November 1, before the days got too short and the weather got too cold.

Supplemental heat was provided in the greenhouse during the last week of the trial, to keep the nighttime temperatures above freezing.

We chose 29 popular microgreens varieties and seeded them each at least 3 times, in order to capture a variety of information (including relative effect of day length on days to maturity and seeds sown/yield).

Each 1020 flat was filled with Johnny's Germination Mix and seeded by eye, weighing the seed packet before and after seeding to determine the exact quantity of seed used per flat.

Each variety was harvested at its first-true-leaf stage. Since this is one of the places where systems can produce differing results, we photographed each variety during one of its harvests so you can compare the appearance to your own desired size at harvest. These photos are posted on the product description pages for each of the 29 individual varieties we trialed. There are links to all 29 varieties from both the seed density and average yield chart and the raw data table, as described below.

Comparison Chart of Average Yield Per Tray & Seed Density (PDF)

Raw Data Table (XLS)

This downloadable spreadsheet can be used as a template to track the results of your own trials and production variables.

Comparison Chart of Averages + Table of Raw Data

For each variety, we provide data on:

• Seeding density
• Yield per tray
• Days to maturity

For the purposes of summarizing our results, we offer our data in two forms: averages and raw.

1. Averages. For those who want a general estimate of yields, we show averages in our Microgreens Yield Trial • Comparison Chart of Average Yield Per Tray & Seed Density (PDF).
2. Raw. For those who want to take a deeper dive into our numbers, we show more detailed data in our Microgreens Yield Trial • Table of Raw Data (XLS).

Some interesting points from that raw data did not make it into the Yield Trial Comparison Chart of Averages, and will be discussed below.

Harvesting 'Gem' Marigold

We found yield to be significantly increased when we allowed this variety to grow a day or two longer beyond development of its first set of true leaves, allowing time for the second set to emerge, before harvesting.

Much of the data gathered were unsurprising.

• Many of the brassicas, like Broccoli, 'Red Russian' Kale, 'Rosie' Pac Choi, and the Mild Micro Mix all yielded similar amounts per flat.
• 'Britton' Shiso, which has a larger seed than many herbs, was seeded at about the same density as a brassica.
• The basil microgreen varieties were all seeded at a similar density, but yielded different totals, mostly due to differences in stem length between varieties, and the purple basils took much longer to reach maturity.

Harvesting 'Garnet Red' Amaranth

Some of the data, however, were surprising.

• Some varieties, like Purple Kohlrabi, took much longer than expected to develop that first true leaf.
• Others, like 'Gem' Marigold, developed them rather quickly, but the yield could be increased dramatically by waiting an additional day or two to harvest before the second set of true leaves emerged.
• 'Garnet Red' Amaranth is quite small, so it's advisable to wait for the second true leaf to emerge, especially if you sow your seeds as thickly as we did. There seemed to be an understory in our flats that grew somewhat slower, and a few days were added to give these individuals a chance to catch up.

The data collected in this trial are intended for use as a jumping-off point. The averages provide rough numbers for you to work with, and the raw data sheet provides a template for further trialing on your own. Try some of these seeding rates, and see how they work for you. Want a larger plant? Use a bit less seed and wait a few more days. Want to harvest at the cotyledon stage? Sow more thickly and harvest earlier. Always be sure to provide sufficient air flow and appropriate temperatures to support your plants.

One important takeaway from the trial is the importance of taking good notes. To replicate or alter the results of any given seeding, you need to be able to see clearly what was done before. Feel free to use our spreadsheet as a template. Decide what information you want to collect, and be sure to include a comments column so you can record anything interesting that you encounter along the way. In this way, trends will emerge that will help you fine-tune your operation and become as profitable as possible.

Learn More

• Growing Information

  • Microgreens • Key Growing Information
  • Microgreens • Production  • Tech Sheet (PDF)
  • Guide to Year-Round Microgreens Production for Profit  • Article

• Variety Selection

  • Microgreens • Fast-Growing Vegetable Varieties  • Comparison Chart (PDF)
  • Microgreens • Slow-Growing Vegetable, Herb & Flower Varieties  • Comparison Chart (PDF)
  • Microgreens • All Varieties  • Comparison Chart (PDF)