Gibberellic Acid (GA₃) – 0.5 g – Seed Dormancy Breaker

Gibberellic Acid (GA₃) is a naturally occurring plant hormone that plays a key role in breaking physiological dormancy, stimulating embryo growth, and initiating germination in slow, dormant, or hard-to-germinate seeds. It is frequently used in place of long stratification periods or combined with warm/cold treatments to achieve faster and more uniform germination.

This vial contains 0.5 g of GA₃, enough to prepare 1 litre of 500 ppm solution, suitable for all applications listed below.

Mixing Instructions (Standard 500 ppm Solution)

Use the full vial (0.5 g) and dissolve into 1 litre of water.

Applications Using a Standard 500 ppm Rate

The following treatment types are commonly used for different seed dormancy mechanisms. All use 500 ppm GA₃ for simplicity and consistency.

1. Pre-Soak Treatment (Before Sowing)

Used for seeds with hard coats or seeds that germinate slowly due to weak endogenous gibberellin signalling.

Procedure:

• Optional: Light scarification or abrasion if the species is known for hard coats.
• Soak seeds in 500 ppm GA₃ for 24 hours.
• Sow immediately after soaking.

Suitable for:

• Capers
• Jujube
• Sea Buckthorn
• Many hard-coated exotic and subtropical species

Purpose:
Enhances embryo expansion, improves initial water uptake, and provides the hormonal cue for radicle emergence.

2. Warm-Soak + GA₃ Treatment

Used for species requiring heat exposure before germinating.

Procedure:

• Warm-water soak for 24 hours (hand-warm, not boiling).
• Follow with a 500 ppm GA₃ soak for 24 hours.
• Sow immediately.

Suitable for:

• Strelitzia (Bird of Paradise) – Scarify → 24 h warm soak → 24 h in GA₃
• Other tropical species with heat-triggered dormancy

Purpose:
Combines thermal softening of the seed coat with hormonal signalling to begin cell elongation.

3. Post-Cold Stratification Soak

For seeds needing winter simulation followed by a germination cue.

Procedure:

• Complete cold stratification (commonly 60–120 days at 4–5 °C).
• After removing seeds from the fridge, soak in 500 ppm GA₃ for 24–48 hours.
• Sow immediately.

Suitable for:

• Pawpaw (Asimina triloba) – After 90+ days stratification
• Temperate species with deep physiological dormancy
• Seeds with inconsistent germination after stratification alone

Purpose:
Provides the hormonal signal normally triggered by spring warming, helping seeds transition from dormancy to active growth.

4. Recovery Treatment for Older or Low-Vigour Seeds

Used when seeds are old, partially viable, or show low germination rates.

Procedure:

• Soak seeds in 500 ppm GA₃ for 24–48 hours before sowing.

Suitable for:

• Aged seed lots
• Slow or uneven germinators
• Seeds with reduced endogenous gibberellin levels

Purpose:
Helps compensate for reduced natural hormone levels in older seeds and improves the chance of germination.

Composition

• Gibberellic Acid (GA₃), ≥ 90% purity
  

Safety Information

• For horticultural use only.
• Avoid contact with eyes and prolonged contact with skin.
• Wear gloves when handling.
• Do not ingest.
• Store sealed in a cool, dry, dark place.
• Keep away from children and pets.