# Gibberellin

> A family of plant hormones (gibberellins, GA) that promote stem elongation, seed germination and, in cannabis, can shift sex expression toward male flowers.

- Canonical: https://genetixbay.com/knowledge/glossary/gibberellin.html
- Also written: gibberellins, GA, GA3, gibberellic acid
- Glossary category: Plant biology · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Gibberellins are diterpenoid plant hormones; more than a hundred are known, a few of which (such as GA1, GA3, GA4) are biologically active. They promote stem and [internode](https://genetixbay.com/knowledge/glossary/internode.md) elongation, break seed dormancy by triggering enzymes that mobilise seed reserves, and influence flowering and sex expression.

## In practice

Gibberellin activity sits behind much of the early-flower [stretch](https://genetixbay.com/knowledge/glossary/stretch.md) and shade-avoidance elongation. Many plant growth regulators sold to keep plants short work by blocking gibberellin synthesis. These are best avoided on a consumable crop.

In cannabis sex expression, gibberellic acid (GA3) applied to female plants can induce [male flowers](https://genetixbay.com/knowledge/glossary/staminate-flower.md). Historically it was one of the methods for producing pollen from females, though silver compounds ([silver thiosulfate](https://genetixbay.com/knowledge/glossary/sts.md), silver [nitrate](https://genetixbay.com/knowledge/glossary/nitrate.md)), which block [ethylene](https://genetixbay.com/knowledge/glossary/ethylene.md) action, are far more reliable for feminised-seed work.

Gibberellin seed soaks are used on dormant seed of some crops. Fresh, healthy [cannabis seed](https://genetixbay.com/knowledge/glossary/achene.md) rarely needs them.

## Don't confuse with

- **Auxin**: drives elongation and rooting through a different pathway.
- **Ethylene**: in cannabis, promotes female flowering and ripening.
- **Stretch**: the growth response; gibberellin is one of its drivers.

## Related terms

[Auxin](https://genetixbay.com/knowledge/glossary/auxin.md), [Internode](https://genetixbay.com/knowledge/glossary/internode.md), [Ethylene](https://genetixbay.com/knowledge/glossary/ethylene.md), [Hermaphrodite](https://genetixbay.com/knowledge/glossary/hermaphrodite.md)

## Read more

- [Stretchy, leggy cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/stretching.md)
- [Feminised seed and sex reversal: methods, with safety notes](https://genetixbay.com/knowledge/breeding/feminised-seed-sex-reversal.md)

## Sources

1. Taiz L, Zeiger E, Møller IM, Murphy A. 2015. Plant Physiology and Development, 6th edition. Sinauer Associates.
2. Ram HYM, Sett R. 1982. Induction of fertile male flowers in genetically female Cannabis sativa plants by silver nitrate and silver thiosulphate anionic complex. Theoretical and Applied Genetics 62:369-375. https://doi.org/10.1007/BF00275107