Organic Oat Grass Microgreen Seeds

Organic Oat Grass is grown as a dense tray crop and harvested as fresh green blades. Unlike whole-oat sprouts, the soaked grain is sown onto a growing medium, rooted into the tray and grown under light before the grass is cut above the seed layer.

What You Need

• Organic Oat Grass Microgreen Seeds
• A 25 × 50cm tray with drainage holes
• A solid lower tray for bottom watering
• Coco coir, fine seed-raising mix or another suitable growing medium
• A clean soaking container
• Clean drinking-quality water
• 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 tray, use approximately:

180–220g dry oat seed per tray

Measure the seed before soaking.

Oats are large cereal grains and require substantially more seed by weight than small-seeded microgreens.

After soaking, spread the swollen grains into a dense, even layer while avoiding thick piles.

Pre-Soak

Pre-soak for approximately:

4–8 hours

1. Measure the required dry seed.
2. Rinse thoroughly with clean drinking-quality water.
3. Place the grain in a clean container.
4. Cover generously with cool water.
5. Soak for approximately 4–8 hours.
6. Drain thoroughly before sowing.

The grain should be well hydrated but not sitting in excess water when transferred to the tray.

Prepare the Growing Medium

Suitable growing media include:

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

Add approximately 2–3cm of growing medium when using soil or coco.

Level the surface and moisten thoroughly.

The medium should be evenly damp without being waterlogged.

Sow the Oats

1. Drain the soaked oats thoroughly.
2. Spread approximately 180–220g dry-seed equivalent evenly across the tray.
3. Aim for a dense single layer.
4. Break up thick piles or heavily overlapping areas.
5. Press the grain gently against the growing medium.
6. Apply a very light covering of fine growing medium or vermiculite if preferred.
7. Cover the tray during early establishment.

Good contact with the growing medium helps roots establish quickly and produces a more even stand of grass.

Covered Germination

Keep the tray covered for approximately:

3–4 days

Use another tray or suitable blackout cover.

Heavy weighting is unnecessary.

During this stage, roots develop into the growing medium while pale shoots begin extending upward.

Check the crop daily and remove the cover once the shoots are well established and pushing strongly upward.

For more information about covered germination, see Microgreen Blackout Explained.

Germination

Expect approximately:

2–4 days

Roots generally emerge first, followed by pale shoots.

Because the grain has already absorbed substantial moisture during soaking, avoid keeping the seed layer permanently saturated.

Temperature

Aim for approximately:

16–25°C

Oat grass performs well under moderate temperatures and generally does not require excessive warmth.

Avoid hot, stagnant conditions combined with very high humidity.

Move the Tray into Light

Once the shoots are established:

1. Remove the blackout cover.
2. Place the tray under bright indirect natural light or suitable grow lights.
3. Maintain good airflow.
4. Rotate the tray if required for even growth.

The pale shoots should rapidly turn green after exposure to light.

Good light helps produce strong, upright blades rather than weak or excessively elongated grass.

Watering

Once the roots are established, bottom watering is preferable.

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

When watering:

• keep the growing medium consistently moist;
• avoid permanent saturation;
• do not leave standing water beneath the tray;
• minimise repeatedly soaking the grain layer;
• allow excess water to drain; and
• maintain airflow through and around the crop.

Dense cereal-grass trays can retain considerable moisture near the seed layer, so check the growing medium before adding more water.

Growing a Dense Green Canopy

Once exposed to light, oat grass develops rapidly.

A healthy tray should gradually form:

• strong upright blades;
• fresh green colouring;
• an increasingly dense root mat; and
• relatively even growth across the tray.

If one section grows significantly faster than another, rotate the tray and check for differences in light or moisture.

Tips for Best Results

• Use approximately 180–220g per 25 × 50cm tray.
• Pre-soak for approximately 4–8 hours.
• Drain thoroughly before sowing.
• Spread the grain evenly.
• Avoid thick piles of overlapping seed.
• Keep covered for approximately 3–4 days.
• Expect germination in approximately 2–4 days.
• Maintain approximately 16–25°C.
• Move into bright light once established.
• Maintain good airflow.
• Bottom water once rooted.
• Avoid permanently wet grain.
• Harvest at approximately 8–12 days.

Avoid Excessively Thick Seed Layers

A dense stand is desirable for oat grass, but more seed does not automatically produce a better crop.

Excessively thick layers can:

• trap moisture;
• restrict airflow around the grain;
• create uneven rooting;
• encourage weak growth; and
• increase the likelihood of grain deterioration.

Use 180–220g per tray as the starting range and distribute it as evenly as possible.

Watch Moisture Around the Grain

Large soaked oat grains retain substantial moisture.

During early establishment, do not compensate for their large size by continually adding water.

The growing medium should remain moist, but the grain itself should not sit in stagnant water.

Once a strong root mat forms, bottom watering provides the roots with moisture without unnecessarily soaking the grain and foliage.

Root Hairs vs Mould

Fine white root hairs may sometimes appear around newly established cereal roots.

Healthy root hairs generally:

• grow directly from individual roots;
• appear relatively evenly;
• become more noticeable as roots dry slightly; and
• become less obvious immediately after watering.

Mould is more likely to:

• spread irregularly between grains;
• form web-like patches;
• remain visible after watering; or
• occur with soft grain, discolouration or unpleasant smells.

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

Discard any tray showing clear signs of spoilage.

Harvest

Harvest approximately:

8–12 days from sowing

Oat grass is generally ready when:

• blades are bright green;
• growth is upright and dense;
• shoots are approximately 10–15cm tall;
• blades remain fresh rather than coarse or drying; and
• the crop has developed its mild fresh grass aroma.

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

Do not pull the plants from the tray or include the oat grains and growing medium in the harvest.

For more detailed cutting and storage guidance, see How to Harvest & Store Microgreens.

Using Fresh Oat Grass

Oat grass becomes increasingly fibrous as it develops.

It is therefore better suited to cutting and juicing than being eaten whole like leafy microgreens.

Harvest close to the time of use where practical.

Harvest & Storage

For short refrigerated storage:

1. Harvest when the blades are relatively dry.
2. Keep cut grass as dry as practical.
3. Place loosely in a clean container.
4. Refrigerate promptly.
5. Avoid crushing or tightly compressing the blades.

Freshly cut oat grass is generally best used soon after harvesting.

Clean Growing / Food Safety

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

Pay particular attention to:

• thoroughly rinsing grain before soaking;
• complete drainage after soaking;
• avoiding overly thick seed layers;
• maintaining good airflow;
• avoiding standing water;
• keeping harvesting equipment clean; and
• refrigerating cut grass promptly when it is not used immediately.

Discard oat grass showing:

• visible mould;
• slime;
• deteriorating grain;
• abnormal discolouration;
• sour or musty smells; or
• other signs of spoilage.

If the harvested grass will be consumed as raw juice, careful hygiene throughout soaking, growing, harvesting and preparation is particularly important.

Seed Storage

Store unused oat 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.