Mint Microgreen Seeds

Mint is a slow-growing specialty microgreen with delicate green foliage and a concentrated fresh mint aroma. Its exceptionally small seed is surface-sown, requires no pre-soaking and should receive light throughout germination.

What You Need

• Mint Microgreen Seeds
• A shallow tray with drainage holes
• A solid lower tray for bottom watering
• Fine seed-raising mix, coco coir or another fine microgreen growing medium
• Clean drinking-quality water
• Fine mist sprayer
• Optional clear humidity dome
• Bright natural light or suitable grow lights
• Clean scissors

Seed Rate

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

0.5–1g dry seed per tray

Mint seed is extremely fine, with approximately 10,000–15,000 seeds per gram.

Spread the seed thinly and as evenly as possible. Do not attempt to create the dense visible seed layer used for broccoli, radish, peas or sunflower.

Because the crop remains in the tray for considerably longer than many common microgreens, excessive density can reduce airflow and make moisture management more difficult.

Pre-Soak

No pre-soaking required.

Sow Mint seed dry.

The tiny seeds are easier to distribute evenly while dry and do not require soaking before sowing.

Step-by-Step Instructions

1. Clean the equipment. Wash and thoroughly rinse the tray, lower watering tray, humidity cover and growing tools.
2. Prepare the growing medium. Add approximately 2–3cm of fine seed-raising mix, coco coir or another suitable fine-textured medium.
3. Moisten thoroughly. Water the medium evenly and allow excess water to drain. The surface should be consistently damp without being saturated.
4. Measure the seed. Use approximately 0.5–1g for a 25 × 50cm tray.
5. Surface sow. Sprinkle the seed as evenly as possible across the growing surface.
6. Do not bury the seed. Leave it exposed at the surface.
7. Press very gently if required. Ensure the seed contacts the moist surface without pushing it beneath the growing medium.
8. Mist carefully. Use a very fine spray so the seed is not washed into clusters.
9. Provide light immediately. Place the tray in bright indirect natural light or beneath suitable grow lights.
10. Use a clear humidity dome if needed. This can help maintain surface moisture while still allowing light to reach the seed.
11. Check moisture regularly. Surface-sown Mint seed must not repeatedly dry out during germination.
12. Ventilate the dome. Once germination begins, increase ventilation and remove the cover as seedlings establish.
13. Bottom water once rooted. As the root system develops, switch primarily to watering from below.

Blackout

Do not use a dark blackout period.

Mint seed requires access to light during germination.

Do not place the tray beneath:

• an opaque blackout lid;
• an inverted dark tray; or
• a weighted germination tray.

Instead, use a clear humidity dome if additional moisture retention is required.

For more information about why some crops use darkness while others do not, see Microgreen Blackout Explained.

Germination

Expect approximately:

7–14 days

Mint can emerge gradually and somewhat unevenly.

Do not assume the crop has failed if only a small number of seedlings are initially visible.

Maintain steady moisture and adequate light rather than increasing watering because germination appears slow.

Temperature

Aim for approximately:

20–24°C

Moderately warm conditions support reliable Mint germination.

Avoid excessive heat combined with persistent humidity or saturated growing media.

Light

Mint should receive light from sowing onward.

Provide:

• bright indirect natural light or suitable grow lights;
• consistent daily light;
• gentle airflow once seedlings emerge; and
• protection from excessive heat through windows.

As the crop develops, the first true leaves become serrated and increasingly recognisable as mint foliage.

Watering

During germination:

• use a very fine mist where required;
• keep the seed surface consistently moist;
• avoid repeatedly allowing the surface to dry;
• do not flood the tray; and
• avoid washing the tiny seed into dense patches.

Once roots establish, 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 the medium before watering again;
• do not leave standing water permanently beneath the tray; and
• maintain good airflow.

Tips for Best Results

• Use approximately 0.5–1g per 25 × 50cm tray.
• Do not pre-soak.
• Surface sow.
• Do not bury the seed.
• Do not use a dark blackout.
• Provide light throughout germination.
• Expect germination in approximately 7–14 days.
• Maintain approximately 20–24°C.
• Keep the surface consistently moist.
• Use a clear humidity dome where required.
• Ventilate once seedlings emerge.
• Bottom water once roots establish.
• Allow true leaves to develop before harvest.

Be Patient with Germination

Mint is considerably slower than broccoli, kale, radish or mustard.

Uneven emergence does not necessarily indicate poor seed.

Continue providing appropriate temperature, surface moisture and light while the remaining seeds germinate.

Avoid Over-Seeding

The recommended 0.5–1g per tray may look unusually low, but each gram contains thousands of individual Mint seeds.

Adding substantially more seed can create excessive competition and a dense, humid crop during the relatively long growing cycle.

True-Leaf Development

Mint is particularly useful as a micro herb once the first recognisable true leaves appear.

The initial cotyledons are small and relatively simple. As the crop develops:

• true leaves become more visibly serrated;
• the foliage takes on a more recognisable Mint appearance; and
• the characteristic fresh aroma becomes stronger.

Root Hairs vs Mould

Fine white root hairs may occasionally be mistaken for mould.

Healthy root hairs generally:

• grow directly from individual roots;
• have a relatively even appearance;
• become more visible as roots dry slightly; and
• become less noticeable immediately after watering.

Mould is more likely to:

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

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

Discard crops showing obvious signs of spoilage.

Harvest & Storage

Harvest approximately:

18–30 days from sowing

Mint is best treated as a specialty micro herb and allowed to develop some recognisable true foliage before harvesting.

Harvest when:

• seedlings are healthy and fresh green;
• the first serrated true leaves have developed;
• the crop has a noticeable fresh Mint aroma;
• shoots are approximately 3–7cm tall; and
• the foliage has reached your preferred size.

Cut cleanly just above the growing medium using clean scissors.

Where practical, harvest when the foliage is relatively dry.

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

Refrigerate promptly in a clean container. Avoid crushing or tightly packing the delicate leaves.

Culinary Use

Fresh Mint microgreens work particularly well with:

• fruit;
• desserts;
• yoghurt;
• salads;
• cakes;
• cold drinks;
• iced tea;
• sauces; and
• fresh garnishes.

Use them fresh or add immediately before serving to preserve their aroma and delicate texture.

Growing Mint to Maturity

Mint can also be grown beyond the microgreen stage.

For mature herb production:

1. Sow the fine seed at a much lower density.
2. Surface sow into moist seed-raising mix.
3. Provide light during germination.
4. Transplant established seedlings into pots or suitable garden positions.
5. Grow in full sun to partial shade.
6. Maintain reasonably moist, freely draining soil.

Container growing is particularly useful because established Mint plants can spread vigorously.

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

Seed Storage

Store unused Mint 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.