# Canopy

> The canopy is the top layer of foliage and buds across a grow, the surface that intercepts most of the light and where yield is mostly made.

- Canonical: https://genetixbay.com/knowledge/glossary/canopy.html
- Also written: plant canopy, the canopy, canopy level, canopy area
- Glossary category: Cultivation and training · 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"

The canopy is the upper surface of foliage formed by all the plants in a space. Light from overhead fixtures is measured at canopy level, and most of the plant's [photosynthesis](https://genetixbay.com/knowledge/glossary/photosynthesis.md) and most of its large buds happen within the top 30-45 cm (12-18 in) or so. Canopy area, the floor area the canopy covers, is also how commercial [yields](https://genetixbay.com/knowledge/glossary/yield.md) and licences are measured.

## In practice

Growers manage the canopy by training (topping, [LST](https://genetixbay.com/knowledge/glossary/lst.md), [SCROG](https://genetixbay.com/knowledge/glossary/scrog.md)), by pruning what sits below it, and by setting the light height so [PPFD](https://genetixbay.com/knowledge/glossary/ppfd.md) is right at the top: typically about 600-1,000 µmol/m²/s in flower without added CO₂. A dense canopy blocks light from lower branches, which is why the growth beneath it is often [lollipopped](https://genetixbay.com/knowledge/glossary/lollipopping.md).

"[Canopy temperature](https://genetixbay.com/knowledge/glossary/leaf-temperature.md)" or "leaf temperature" readings come from this layer.

## Don't confuse with

- **Even canopy**: a canopy where all tops sit at the same height.
- **Grow area**: the tent or room floor; canopy area can be smaller if plants don't fill it.

## Related terms

[Even canopy](https://genetixbay.com/knowledge/glossary/even-canopy.md), [SCROG](https://genetixbay.com/knowledge/glossary/scrog.md), [PPFD](https://genetixbay.com/knowledge/glossary/ppfd.md), [Lollipopping](https://genetixbay.com/knowledge/glossary/lollipopping.md), [Plant density](https://genetixbay.com/knowledge/glossary/plant-density.md)

## Read more

- [PPFD and DLI by stage, with the evidence](https://genetixbay.com/knowledge/environment/ppfd-dli-by-stage.md)

## Sources

1. Westmoreland FM, Kusuma P, Bugbee B., 2021. Cannabis lighting: Decreasing blue photon fraction increases yield but efficacy is more important for cost effective production of cannabinoids. PLOS ONE 16(3):e0248988. https://doi.org/10.1371/journal.pone.0248988