# Mainlining

> Mainlining is a training method that tops a plant low, removes lower growth and splits it symmetrically into a set number of evenly sized main colas.

- Canonical: https://genetixbay.com/knowledge/glossary/mainlining.html
- Also written: main-lining, main lining, mainline
- Glossary category: Cultivation and training · Evidence: Grower practice
- 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"

Mainlining is a structured training system that combines low topping, removal of all growth below the topping point, and repeated symmetrical topping so that every main stem is fed from a single central "hub". The result is a plant with 4, 8 or 16 identical [colas](https://genetixbay.com/knowledge/glossary/cola.md) sitting at the same height.

## In practice

Top above the third node, strip everything below, tie the two remaining shoots horizontally, then top each again to make four, then eight. Each branch draws evenly from the hub, so buds tend to be uniform. The cost is time: mainlining typically adds about two to four weeks of veg compared with an untrained plant. It suits [photoperiods](https://genetixbay.com/knowledge/glossary/photoperiod.md) and [SCROG](https://genetixbay.com/knowledge/glossary/scrog.md); it is a poor fit for [autoflowers](https://genetixbay.com/knowledge/glossary/autoflower.md).

Evidence is grower practice. Cannabis research does show that plant architecture affects how uniform [cannabinoid](https://genetixbay.com/knowledge/glossary/cannabinoid.md) content is across the canopy, which supports the logic of even colas.

## Don't confuse with

- **Manifolding**: often used as a synonym; some growers reserve it for the hub-and-arms shape specifically.
- **Mainline (drugs)**: unrelated.

## Related terms

[Manifolding](https://genetixbay.com/knowledge/glossary/manifolding.md), [Topping](https://genetixbay.com/knowledge/glossary/topping.md), [LST](https://genetixbay.com/knowledge/glossary/lst.md), [Even canopy](https://genetixbay.com/knowledge/glossary/even-canopy.md)

## Read more

- [Mainlining and manifolding: building a symmetrical plant](https://genetixbay.com/knowledge/training/mainlining-manifolding.md)

## Sources

1. Danziger N, Bernstein N, 2021. Shape matters: plant architecture affects chemical uniformity in large-size medical cannabis plants. Plants 10(9):1834. https://pmc.ncbi.nlm.nih.gov/articles/PMC8468686/