Purple Tatsoi Microgreen Seeds

Seeding Rate

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

10–12g of dry seed per tray

Spread the seed evenly over the growing surface.

Avoid excessively dense patches. Moderate spacing improves airflow and allows the young leaves to develop stronger colour and a more defined Tatsoi shape.

Pre-Soak

No pre-soaking required.

Sow the seed dry directly onto the prepared growing medium.

Tatsoi is a small brassica seed and normally hydrates readily once placed onto a consistently moist surface.

Step 1 – Prepare the Growing Medium

Suitable growing media include:

• Coco coir
• Fine seed-raising mix
• Fine propagation mix
• Quality soil-based microgreen mix
• Vermiculite as part of the medium or as a light surface covering
• Suitable hydroponic or fibre growing mats

When using soil or coco, add approximately 2–3cm of growing medium.

Level the surface and moisten evenly before sowing.

The medium should be damp without being waterlogged.

Step 2 – Sow the Seed

1. Measure approximately 10–12g of dry seed.
2. Spread evenly across the prepared growing surface.
3. Break up any dense patches.
4. Press the seed gently into contact with the medium.
5. Mist lightly with clean drinking-quality water.
6. Apply a very light covering of vermiculite if preferred.
7. Cover the tray during early germination.

Do not bury deeply.

Blackout Time

Keep the tray covered for approximately:

2–3 days

A second tray or suitable blackout cover can be used.

Heavy weighting is unnecessary.

Remove the cover once most seedlings have germinated and are beginning to push upwards.

Germination Time

Expect approximately:

3–7 days

Radicles can appear earlier under favourable conditions, but allow several days for the tray to establish evenly.

Maintain consistent moisture without saturating the growing medium.

Ideal Growing Temperature

Aim for approximately:

18–24°C

Tatsoi performs well under cool to moderate growing conditions.

Purple pigmentation is produced by anthocyanins. Research across purple Brassica rapa crops shows that cooler conditions can increase anthocyanin accumulation, so colour may become more intense under cooler growing conditions.

Do not deliberately expose seedlings to damaging cold solely to increase colour.

Step 3 – Introduce Light

Once the seedlings are established:

1. Remove the cover.
2. Place the tray under bright indirect natural light or suitable grow lights.
3. Maintain good airflow.
4. Rotate the tray where necessary for even development.

Colour should strengthen as the crop develops.

Depending on growing conditions, foliage may show:

• Green during very early emergence
• Reddish-purple tones developing progressively
• Burgundy to deeper purple upper foliage
• Contrasting green tones or undersides

Good light is important for producing compact plants and strong colour.

Step 4 – Watering

During early germination, mist gently if required.

Once roots establish, bottom watering is preferable.

• Keep the growing medium consistently moist.
• Avoid permanent saturation.
• Do not leave standing water beneath the tray.
• Minimise repeatedly wetting the foliage.
• Maintain good airflow through the crop.

Step 5 – Harvest

Harvest approximately:

10–14 days from sowing

Purple Tatsoi microgreens are generally ready when:

• Cotyledons are fully open
• Purple-red colour is well developed
• Stems remain tender
• Shoots are approximately 4–7cm tall
• Early true leaves may be beginning to develop
• The crop has a fresh, mild mustard flavour

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

Other Ways to Grow Purple Tatsoi

Growing as Baby Leaf

For baby Tatsoi:

1. Sow substantially less densely than for microgreens.
2. Allow individual plants more room.
3. Continue growing beyond the microgreen stage.
4. Provide good light.
5. Maintain consistent moisture.
6. Harvest tender young leaves progressively.

Baby leaves generally develop more strongly defined purple colouring and the characteristic spoon-shaped Tatsoi foliage.

Growing to Full Maturity

Purple Tatsoi can also be grown into mature plants.

For mature growing:

1. Direct sow or raise seedlings in trays.
2. Sow approximately 5–6mm deep.
3. Thin or transplant plants to approximately 20cm apart.
4. Allow approximately 30–40cm between rows.
5. Grow in fertile, well-drained soil.
6. Provide full sun to partial shade.
7. Maintain consistent moisture.

Tatsoi generally prefers cool to mild growing conditions.

Tips for Best Results

Do Not Pre-Soak

Tatsoi seed does not require soaking.

Dry sowing also makes the small seed easier to distribute evenly.

Avoid Over-Seeding

Use approximately 10–12g per 25 × 50cm tray.

Overcrowding can trap moisture, reduce airflow and produce elongated seedlings.

Keep Blackout Short

Approximately 2–3 days is generally enough.

Move established seedlings into light promptly.

Provide Good Light for Purple Colour

Adequate light supports:

• Compact growth
• Stronger foliage
• Better colour development
• More uniform trays

The crop may initially appear greener before purple-red pigmentation becomes more pronounced.

Cooler Conditions Can Strengthen Colour

Purple colouring comes from anthocyanin pigments.

Research on purple Brassica rapa seedlings demonstrates that cooler temperatures can increase anthocyanin accumulation and intensify purple pigmentation.

Normal healthy plant growth remains the priority; avoid severe cold stress.

Allow the First True Leaves to Develop

The crop can be harvested at cotyledon stage, but allowing early true leaves to appear produces:

• More characteristic Tatsoi foliage
• Stronger visual contrast
• More developed purple colour
• A more substantial microgreen

Maintain Good Airflow

Purple Tatsoi forms a compact canopy.

Use good airflow and preferably bottom water once the seedlings establish.

Root Hairs vs Mould

Fine white root hairs can sometimes be mistaken for mould.

Root hairs generally:

• Grow directly from individual roots
• Have a relatively even appearance
• Become more noticeable as the root zone dries slightly
• Become less visible immediately after watering

Mould is more likely to:

• Spread irregularly between seedlings
• Form web-like patches
• Persist after watering
• Occur with slime or discolouration
• Produce unpleasant odours

Discard crops showing clear signs of spoilage.

Key Growing Tips

• Use approximately 10–12g per 25 × 50cm tray.
• Do not pre-soak.
• Sow evenly and shallowly.
• Blackout for approximately 2–3 days.
• Expect germination in approximately 3–7 days.
• Maintain approximately 18–24°C.
• Provide bright light for strong colour.
• Maintain good airflow.
• Bottom water once established.
• Harvest at approximately 10–14 days.

Harvest & Storage

Harvest when the foliage is dry where practical.

Cut cleanly just above the growing medium.

For refrigerated storage:

1. Keep harvested Tatsoi as dry as practical.
2. Place it loosely in a clean container.
3. Refrigerate promptly.
4. Avoid crushing the tender foliage.

If washed before refrigeration, drain and dry thoroughly first.

Food Safety

Use clean equipment, fresh growing medium and drinking-quality water throughout production.

Maintain:

• Clean trays
• Good drainage
• Controlled moisture
• Adequate airflow
• Clean harvesting equipment
• Prompt refrigeration after harvest

Do not consume microgreens showing visible mould, slime, abnormal discolouration, unpleasant odours or other signs of spoilage.