Red Mizuna Microgreen Seeds

Red Mizuna is a fast-growing brassica microgreen with colourful red-purple foliage, finely serrated true leaves and a fresh mild mustard flavour. It requires no pre-soaking and can generally be harvested in approximately 10–14 days.

What You Need

• Red Mizuna Microgreen Seeds
• A shallow tray with drainage holes
• A solid lower tray for bottom watering
• Coco coir, fine seed-raising mix or another suitable microgreen growing medium
• Clean drinking-quality water
• Fine mist sprayer
• A second tray or suitable blackout cover
• Bright natural light or suitable grow lights
• Clean scissors or a sharp harvesting knife

Seed Rate

For a standard 25 × 50cm microgreen tray, use approximately:

10–15g dry seed per tray

Broadcast the seed evenly across the growing surface.

Avoid dense piles or heavily overlapping patches. Moderate density becomes increasingly important as the serrated foliage develops and the canopy becomes more textured.

For more information about adjusting density between crops, see Microgreen Seeding Density.

Pre-Soak

No pre-soaking required.

Sow Red Mizuna seed dry directly onto the prepared growing medium.

The small brassica seed germinates readily without soaking and is much easier to distribute evenly while dry.

Step-by-Step Instructions

1. Clean your equipment. Wash and thoroughly rinse trays, covers and growing tools.
2. Prepare the growing medium. Add approximately 2–3cm of coco coir, fine seed-raising mix or another suitable medium.
3. Moisten before sowing. Water evenly and allow excess water to drain. The medium should be damp throughout without being saturated.
4. Measure the seed. Use approximately 10–15g for a standard 25 × 50cm tray.
5. Sow evenly. Spread the seed across the growing surface and break up any concentrated patches.
6. Press gently. Ensure good contact between the seed and moist growing medium.
7. Mist lightly. Moisten with clean drinking-quality water without flooding the tray.
8. Cover the tray. Place another tray or suitable blackout cover over the crop.
9. Check daily. Maintain even moisture without keeping the growing medium saturated.
10. Uncover once established. Remove the cover when most seedlings are rooted and beginning to push upward.
11. Move into light. Provide bright indirect natural light or suitable grow lights.
12. Maintain airflow. Good airflow becomes increasingly important as the serrated foliage develops.
13. Bottom water once rooted. Switch primarily to watering from below once the root system is established.

Blackout

Keep the tray covered for approximately:

3–5 days

Heavy weighting is unnecessary.

A second tray or light cover is sufficient to maintain darkness and seed-to-medium contact during establishment.

Check the crop each day and uncover once seedlings are well rooted and pushing upward.

Do not leave established seedlings beneath the cover simply to complete a fixed number of days.

For more information, see Microgreen Blackout Explained.

Germination

Expect germination in approximately:

2–4 days

Red Mizuna is generally a fast and relatively even germinator under suitable conditions.

Maintain steady moisture without flooding or saturating the growing medium.

Temperature

Aim for approximately:

18–24°C

Moderate indoor temperatures support rapid germination and compact growth.

Avoid excessive heat combined with stagnant humidity, particularly while the crop remains covered.

Light & Colour Development

Once uncovered:

• provide bright indirect natural light or suitable grow lights;
• rotate the tray if necessary for even growth;
• maintain good airflow;
• avoid excessive heat; and
• avoid leaving the foliage continually wet.

Good light is particularly useful with Red Mizuna because it encourages compact growth and stronger red, burgundy and purple pigmentation.

Weak light can produce more elongated growth and less pronounced colour.

Watering

During early germination, mist gently whenever necessary to maintain even surface moisture.

Once roots are established, bottom watering is preferable.

For detailed guidance, see How to Water Microgreens: Misting vs Bottom Watering.

When bottom watering:

• add a shallow amount of water to the lower tray;
• allow the growing medium to absorb moisture;
• check moisture before watering again;
• do not leave standing water permanently beneath the tray;
• minimise repeated wetting of established foliage; and
• maintain good airflow.

As the serrated foliage develops, avoid keeping the canopy continuously wet.

Tips for Best Results

• Use approximately 10–15g per 25 × 50cm tray.
• Do not pre-soak.
• Sow evenly at moderate density.
• Blackout for approximately 3–5 days.
• Expect germination in approximately 2–4 days.
• Maintain approximately 18–24°C.
• Provide strong light after blackout.
• Maintain good airflow.
• Bottom water once roots establish.
• Avoid saturated growing media.
• Allow the first serrated true leaves to begin developing.
• Harvest at approximately 10–14 days.

Serrated True Leaves

Red Mizuna initially produces relatively smooth cotyledons.

As the crop matures, its first true leaves become increasingly cut and serrated.

Allowing some true-leaf development gives the crop:

• a more recognisable Mizuna appearance;
• greater visual texture; and
• stronger colour contrast.

Root Hairs vs Mould

Fine white root hairs can sometimes be mistaken for mould.

Healthy root hairs generally:

• grow directly from individual roots;
• appear relatively evenly;
• become more visible as the root zone dries slightly; and
• become less obvious immediately after watering.

Mould is more likely to:

• spread irregularly between seedlings;
• form web-like patches;
• persist after watering; or
• occur with slime, decay or unpleasant odours.

If you are uncertain, see Mould vs Root Hairs on Sprouts & Microgreens.

Discard crops showing obvious spoilage.

Harvest & Storage

Harvest approximately:

10–14 days from sowing

Red Mizuna microgreens are generally ready when:

• the crop is upright and healthy;
• red to burgundy-purple colouring is well developed;
• the first serrated true leaves are appearing;
• shoots are approximately 5–8cm tall;
• stems remain tender; and
• the flavour is fresh and mildly peppery.

Cut cleanly just above the growing medium using clean scissors or a sharp harvesting knife.

Where practical, harvest when the foliage is relatively dry.

For additional guidance, see How to Harvest & Store Microgreens.

Refrigerate promptly in a clean container. If washed before refrigeration, drain and dry thoroughly first.

Growing as Baby Leaf

For baby-leaf Mizuna:

1. Sow substantially less densely than for microgreens.
2. Allow more room between plants.
3. Continue growing beyond the microgreen stage.
4. Provide good light.
5. Maintain consistent moisture.
6. Harvest when the serrated leaves reach your preferred size.

Growing to Full Maturity

For mature Mizuna:

1. Direct sow or raise seedlings in trays.
2. Transplant or thin to approximately 15–25cm apart.
3. Grow in fertile, well-drained soil.
4. Provide full sun to partial shade.
5. Maintain regular moisture.
6. Harvest outside leaves progressively.

Mizuna can be treated as a cut-and-come-again leafy green by leaving the central growing point intact.

Clean Growing / Food Safety

Use clean trays, fresh growing medium, drinking-quality water and clean harvesting equipment.

Maintain:

• appropriate moisture;
• good drainage;
• adequate airflow;
• clean harvesting tools; and
• prompt refrigeration after harvest.

Discard crops showing visible mould, slime, decay, abnormal discolouration or unpleasant odours.

Seed Storage

Store unused Red Mizuna seed sealed in a cool, dry and dark place away from heat, moisture and direct sunlight.

For longer-term storage, refrigeration can help maintain seed viability. Keep refrigerated seed sealed while it returns to room temperature before opening to reduce condensation.