By Stephen Beck | February 20, 2025

Grow Your Own Microgreens

Person holding microgreens

What You Will Need

Piles of dirt on a tray

Seeds

Choose seeds labeled for microgreens, such as radish, broccoli, sunflower, or pea shoots.

Growing Trays

A shallow tray with drainage holes works best. You can also use repurposed containers like pie tins or takeout trays; 1020 trays work great for growing microgreens.

Growing Medium

Use a seed-starting mix, coconut coir, or a hydroponic grow mat.

Light Source

Use natural sunlight or a grow light for a light source.

Prepare to Grow

  1. Pre-moisten the coconut coir to the consistency and feel of a wrung-out sponge. Grab a handful and squeeze. Your hand should be wet, but no water should drip out.
  2. Add 2 quarts coconut coir to a 1020 tray with drain holes.
  3. Add 2 cups water to a 1020 tray without drain holes.
  4. Place the tray with coir on top of the tray with water.
  5. After 30 minutes, discard any water remaining in the bottom tray, if any.
  6. For other media types, you’ll perform similar steps.

General Guidelines

Table 1 provides general guidelines for popular microgreens. Notice the short harvest intervals and that the various types offer a broad range of flavors.

Microgreen variety Seeding (g/1020 tray) Seed presoak Covered time Estimated time to harvest Seed cost per pound* Seed cost per tray Flavor
Arugula 10 no 1-2 days 6-8 days $13.26 $0.30 peppery
Basil 28 no 4-7 days 12-16 days $28.84 $1.80 intense basil
Broccoli 28 no 2-4 days 8-12 days $14.17 $0.89 mild broccoli
Cilantro 28 no 7-14 days 21-28 days $25.56 $1.60 cilantro
Kale 28 no 1-2 days 8-12 days $14.51 $0.91 strong brassica, nutty
Mesclun greens mix 28 no 3-5 days 12-14 days $23.52 $1.47 mild, slightly sweet
Pea 150 6 hours 3 days 8-10 days $7.98 $2.67 Sweet pea
Radish (champion) 42 no 1-2 days 8-12 days $14.17 $1.33 nutty, spicy
Radish (purple) 42 no 1-2 days 8-12 days $36.58 $3.43 nutty, spicy
Rutabaga 28 no 1-2 days 8-12 days $11.29 $0.71 mild peppery mustard
Sunflower 48 12 hours 3 days 9-10 days $9.02 $0.97 nutty, sweet

*Seed cost based on prices as of 12/17/2024

Plant Seeds

  1. Weigh an appropriate amount of seed for the variety.
  2. Evenly distribute the seed across the media.
  3. Cover the media with another 1020 tray, placed directly on the media. Place something flat and heavy on top (2–5 pounds).

Germinate in the Dark

Small seedlings growing out of dirt

For the first part of germination, the tray will be kept in the dark with another tray directly on top. Additional weight (like a piece of plywood cut to fit in a 1020 tray) will help the seeds to remain in contact with the media while the roots push down into it. Leave it directly in contact with the media for half of the dark period (see “Covered Time” in Table 1). The goal is to ensure the roots are forced to grow downward, rather than pushing the seed upward. Remove the tray when it’s obvious the roots are pushing into the medium.

For the second half of the dark period, take the top tray off and turn it over so that it forms a covering without contacting the seeds. At this point, the plants will begin sprouting. They are kept in the dark for a period to encourage them to stretch a bit.

Turn On the Lights

Artificial lights give you the most control, but a southern exposed window can also work. Remember that during winter, Utah has as little as 8 hours of sunlight per day.

Grow lights should be connected to a timer and turned on 18 hours per day. Remember: lights on for 18 hours, dark for 6 hours.

Temperature

Ensuring the planting medium stays at adequate temperatures can help the microgreen seeds germinate successfully. The light source will provide some heat. If needed, using a heating pad designed for starting seeds can help you achieve optimal temperatures in a cooler environment.

  • 74 °F during germination.
  • 72 °F during lights on.
  • 68 °F during lights off.

Airflow

Plants need constant airflow. Use a gentle-blowing fan, especially if your plants are near a sunny window.

Harvest

Plants are ready to harvest as soon as you begin to see the first true leaves, or sooner. Experiment to see what you like best.

References

February 2025
Utah State University Extension

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Authors

Stephen Beck

Stephen Beck

Stephen Beck

Diagnostician | Gardening Help Desk

Horticulture

Phone: 385-468-4828
Office Location: Room 300 Salt Lake County
 

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