Morus alba – White Mulberry

Seed germination instructions

Morus alba (White Mulberry) seeds may exhibit physiological dormancy. For more uniform and reliable germination, moist cold stratification for approximately 60–90 days is recommended.

Requirements may vary between seed lots depending on freshness, provenance and storage conditions.

1. Seed soaking

Before stratification, hydrate the seeds:

1. Place the seeds in a clean container.

2. Cover them with room-temperature water.

3. Soak for approximately 12–24 hours.

4. Drain the seeds thoroughly after soaking.

Soaking helps ensure that the seeds are evenly hydrated before stratification.

2. Cold stratification

Prepare a slightly moist medium such as vermiculite, perlite, clean horticultural sand, or a mixture of coconut coir and perlite.

1. Mix the seeds with the slightly moist medium.

2. Place the seeds and medium in a sealed plastic bag or closed container.

3. Keep them in a refrigerator at approximately 2–5°C (36–41°F).

4. Stratify for approximately 60–90 days.

5. Check the seeds every 1–2 weeks to ensure that the medium remains slightly moist and to monitor for mould.

The medium should be moist but not wet or waterlogged.

If a seed begins to germinate during stratification, carefully sow it immediately, taking care not to damage the emerging root.

3. Sowing

After completing the stratification period, sow the seeds as soon as possible.

1. Prepare a light, well-drained and well-aerated seed-starting medium.

2. Place the seeds on the surface of the medium.

3. Cover them with a very thin layer of growing medium, approximately 2–5 mm (0.08–0.2 in) deep.

4. Gently moisten the medium.

5. Place the container in a bright location.

Do not sow the seeds deeply. A shallow sowing depth is recommended for White Mulberry.

4. Germination conditions

After sowing, maintain consistent moisture. Do not allow the growing medium to dry out completely, but avoid prolonged waterlogging.

5. Germination time

Under suitable conditions, the first seedlings may appear approximately 1–3 weeks after sowing.

Germination can be uneven and some seeds may require considerably more time.

Some seeds may remain dormant and germinate during a later growing season. Therefore, do not discard unsprouted seeds prematurely.

6. Care of young seedlings

After emergence:

• provide plenty of light,

• maintain moderate and consistent moisture,

• ensure good air circulation,

• avoid overwatering,

• protect very young seedlings from excessive heat and intense direct sunlight.

Once the seedlings have developed several true leaves and an adequately developed root system, they can be carefully transplanted into individual pots.

7. Fertilization

Do not fertilize immediately after germination.

Approximately 4–6 weeks after emergence, once the seedlings are well established, begin light fertilization using a balanced fertilizer at approximately 1/4 of the manufacturer's recommended dosage.

8. Common mistakes to avoid

• Skipping stratification when the seed lot requires dormancy-breaking treatment.

• Using an excessively short stratification period.

• Allowing the seeds to dry out during stratification.

• Keeping the seeds in excessively wet or waterlogged medium.

• Sowing the seeds too deeply.

• Excessive watering after sowing.

• Using containers without adequate drainage.

• Fertilizing young seedlings too early or too heavily.

• Discarding seeds prematurely because germination is uneven.

Important information

• Moist cold stratification for approximately 60–90 days is recommended for more uniform germination.

• Recommended stratification temperature: 2–5°C (36–41°F).

• Seeds should remain moist during stratification but must not be submerged in water.

• Dormancy requirements can vary considerably between seed lots.

• Fresh, properly stored seeds generally provide the best results.

• Seeds can also be sown outdoors in autumn, allowing them to experience natural winter conditions before germinating in spring.

• Seeds should be sown shallowly and covered only with a thin layer of growing medium.

• Germination may be uneven, and some seeds may require additional time.

Recommended method for beginners

1. Soak the seeds for 12–24 hours in room-temperature water.

2. Place the seeds in slightly moist vermiculite, perlite, clean sand, or coconut coir mixed with perlite.

3. Cold-stratify for 60–90 days at 2–5°C (36–41°F).

4. After stratification, sow the seeds on the surface and cover them with approximately 2–5 mm (0.08–0.2 in) of growing medium.

5. Maintain approximately 20–22°C (68–72°F), provide a bright location and keep the growing medium consistently slightly moist.

The first seedlings will usually appear within approximately 1–3 weeks after sowing, although some seeds may germinate considerably later.

Note: Failure to germinate within the first few weeks does not necessarily indicate that the seeds are non-viable.