# Purp

> Purp is slang for purple-coloured cannabis; the colour comes from anthocyanins and depends on genetics and cool temperatures, not on potency.

- Canonical: https://genetixbay.com/knowledge/glossary/purp.html
- Also written: purple, purps, purple weed, purple buds, purpz
- Glossary category: Grower slang and culture · Evidence: Myth
- 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"

Purp is slang for purple flower, or a cultivar known for turning purple. The colour comes from anthocyanins, water-soluble pigments that some [genotypes](https://genetixbay.com/knowledge/glossary/genotype.md) produce in leaves, [bracts](https://genetixbay.com/knowledge/glossary/bract.md) and [sugar leaves](https://genetixbay.com/knowledge/glossary/sugar-leaf.md).

## In practice

Genetics decide whether a plant can turn purple. Cool night temperatures in late flower, often a drop to about 15-18 °C (59-64 °F) or below, increase anthocyanin expression in plants that carry the trait. A plant without the genetics stays green however cold it gets.

Purple stems and leaves in veg can also mean other things, including phosphorus or cold stress. See [purple stems and leaves](https://genetixbay.com/knowledge/diagnosis/purple-stems-leaves.md).

## Don't confuse with

- **Purple as a strain family**: many names contain "purple"; the name does not guarantee the colour.
- **Deficiency purpling**: dull purple [petioles](https://genetixbay.com/knowledge/glossary/petiole.md) with other symptoms, not glossy coloured bracts.

## Myth check

"Purple weed is stronger" or "[cold nights](https://genetixbay.com/knowledge/glossary/cold-nights.md) boost terps and resin". GenetixBay position: colour from cold is real; claims of more [terpenes](https://genetixbay.com/knowledge/glossary/terpene.md), flavour or resin are a myth unless peer-reviewed data shows otherwise. [Bag appeal](https://genetixbay.com/knowledge/glossary/bag-appeal.md) is not quality, though the founder admits he is "a sucker for any red strain". See [Mythbusters](https://genetixbay.com/knowledge/mythbusters.md).

## Related terms

[Anthocyanin](https://genetixbay.com/knowledge/glossary/anthocyanin.md), [Bag appeal](https://genetixbay.com/knowledge/glossary/bag-appeal.md), [Cold nights](https://genetixbay.com/knowledge/glossary/cold-nights.md)

## Read more

- [Purple or red stems and leaves on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/purple-stems-leaves.md)