# Apical dominance

> The suppression of side-shoot growth by the main growing tip, driven mainly by auxin flowing down the stem from the apex.

- Canonical: https://genetixbay.com/knowledge/glossary/apical-dominance.html
- Also written: apical control, top dominance, leader dominance
- 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"

Apical dominance is the tendency of the main [shoot tip](https://genetixbay.com/knowledge/glossary/apical-meristem.md) to grow fastest while holding back the buds and branches below it. [Auxin](https://genetixbay.com/knowledge/glossary/auxin.md) made in the apex moves down the stem and, together with cytokinin and strigolactone signalling, keeps [axillary buds](https://genetixbay.com/knowledge/glossary/axillary-bud.md) dormant or slow. The result is a single-leader, "Christmas tree" shape.

## In practice

Almost every training method is a way of breaking or redirecting apical dominance:
- **Topping** and **FIM** remove the apex, releasing the buds below.
- **[LST](https://genetixbay.com/knowledge/glossary/lst.md)** bends the leader down so that side branches sit as high and receive as much auxin relief and light as the top.
- **Mainlining** and **manifolding** combine topping with symmetrical shaping.
- **[SCROG](https://genetixbay.com/knowledge/glossary/scrog.md)** spreads every tip level under a net.

Cultivars differ a lot. Some have strong apical dominance and grow one fat [main cola](https://genetixbay.com/knowledge/glossary/cola.md); others branch freely on their own. [Autoflowers](https://genetixbay.com/knowledge/glossary/autoflower.md), which can't spare recovery time, are better shaped by LST than by topping (house position).

## Don't confuse with

- **Apical meristem**: the tissue; apical dominance is its effect.
- **Phototropism**: bending toward light, a separate auxin response.
- **Stretch**: elongation in early flower, not branch suppression.

## Related terms

[Apical meristem](https://genetixbay.com/knowledge/glossary/apical-meristem.md), [Auxin](https://genetixbay.com/knowledge/glossary/auxin.md), [Cytokinin](https://genetixbay.com/knowledge/glossary/cytokinin.md), [Axillary bud](https://genetixbay.com/knowledge/glossary/axillary-bud.md), [Cola](https://genetixbay.com/knowledge/glossary/cola.md)

## Read more

- [Topping: cutting the main tip for more colas](https://genetixbay.com/knowledge/training/topping.md)
- [LST: low-stress training](https://genetixbay.com/knowledge/training/lst.md)

## Sources

1. Taiz L, Zeiger E, Møller IM, Murphy A. 2015. Plant Physiology and Development, 6th edition. Sinauer Associates.