How to Grow Mustard Microgreens: Warm Peppery Kick

Mustard is quick and undemanding: it needs a blackout of only 1 to 2 days before it goes under light, and it is ready to cut 6 to 10 days after sowing. This guide, like the others in our series on individual varieties, covers the characteristics of the crop, step by step instructions, and practical notes from our own growing.

As we mentioned in the previous article, we’ve had great results in the office growing broccoli, lettuce, mustard, and red amaranth. Now we’re expanding our little indoor garden with green peas, wheatgrass, and sunflowers.

Mustard microgreens are perfect for adding a spicy kick to salads, sandwiches, or soups.

Table of Contents

What do you need?

Mustard seeds: Easy to find in specialty stores or online.
Growing trays: Flat trays, with or without drainage holes.
Growing medium: Potting soil or another suitable substrate.
Spray bottle or watering can
Natural light or LED grow lights: Mustard microgreens love light! As we mentioned, in our office we use artificial light, but sunlight is also an excellent option.

Step by step guide to growing mustard microgreens

1. Prepare the tray

Clean it thoroughly before using, water and soap if needed.

2. Add the substrate

Fill the tray with soil and moisten it evenly.

3. Sow the seeds

Spread the mustard seeds evenly across the surface. No need to cover them, just press them gently to ensure good contact with the soil.

4. Mist with water

Use a spray bottle to moisten without moving the seeds. The key is to keep the surface damp, not soaked.

5. Blackout period

Cover the tray for the first 1–2 days to promote germination. You can use another tray or a piece of cardboard.

6. Light and ventilation

Once you see the first sprouts (usually by day 3), uncover the tray and place it in a well lit spot or under grow lights.

7. Keep it moist

Water gently once or twice a day, depending on how dry the substrate gets.

8. Harvest time!

After 6 to 10 days, your mustard microgreens will be ready. Use clean scissors to cut just above the soil line. The leaves should be vibrant and spicy in flavor.

Dense tray of mustard microgreens seen from above, with rounded green cotyledons on pale stems

Mustard microgreens are quick, easy to grow, and full of flavor. Plus, they’re packed with nutrients like vitamins A, C, and K, and powerful antioxidants.

In our next post, we’ll share our experience growing red amaranth microgreens, which are not only nutritious but also incredibly decorative.

The science on mustard

Studies from our Science Library that concern mustard microgreens, in plain language with links to the original research. This list updates automatically as new studies are added.

No studies specific to this crop yet — browse the full Science Library.

Mustard in the kitchen

Recipes and kitchen ideas from our cookbook team that use mustard microgreens.

No recipes for this crop yet — the cookbook has plenty to start with.

Growing a different crop next? Every variety has a guide like this one in the Varieties database.

The science behind this crop

Our research archive holds 38 peer-reviewed studies on mustard microgreens. They are free to read and download, and each one credits its original authors.