Glossary

Plain-language definitions for the terms we use.

Anthocyanin
Water-soluble flavonoid pigments stored in plant cell vacuoles. They produce the purple, red and blue tones in cannabis, and are unrelated to cannabinoids.
Botrytis cinerea
The fungus behind bud rot. It germinates in prolonged leaf wetness at high humidity, in roughly the same temperature range that induces anthocyanin.
Chlorophyll
The dominant green pigment in plant tissue. As it degrades in late flower, anthocyanins underneath become visible — which is why purpling can look sudden.
Cultivar
A specific cultivated variety maintained by propagation. It is the precise term for what is loosely called a "strain".
Dew point
The temperature at which saturation occurs and water condenses. Sizing dehumidification to a target dew point is more reliable than targeting a humidity percentage.
Senescence
The natural winding-down at the end of a plant's life cycle, when nitrogen moves out of the leaves and chlorophyll breaks down.
Trichome
The resin gland on cannabis flower where cannabinoids and terpenes are produced. Trichome density is a far better visual proxy for potency than color.
Vapor pressure deficit
The gap between how much moisture the atmosphere holds and how much it could hold. When VPD collapses, transpiration stalls and calcium stops reaching developing tissue.

Looking for terpenes? They have their own section.