# Taco leaf

> A leaf whose edges fold upward along the midrib like a taco shell or canoe, usually at the top of the canopy; a sign of heat, high VPD or excess light.

- Canonical: https://genetixbay.com/knowledge/glossary/taco-leaf.html
- Also written: tacoing, taco leaves, canoeing, canoe leaves, leaf tacoing
- Glossary category: Plant biology · Evidence: Supported
- 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"

Tacoing or canoeing is an upward fold of the [leaflet](https://genetixbay.com/knowledge/glossary/leaflet.md) along its midrib so the edges point toward the light. Plants do this to reduce the leaf area facing intense light and to cut water loss when leaves are hot or the air is dry. [Leaf temperature](https://genetixbay.com/knowledge/glossary/leaf-temperature.md) depends on air temperature, radiation, airflow and [transpiration](https://genetixbay.com/knowledge/glossary/transpiration.md) (Nelson and Bugbee 2015).

## In practice

Check where it occurs. At the top of the canopy, under the fixture or in hot spots, it points to heat, high [VPD](https://genetixbay.com/knowledge/glossary/vpd.md) or too much light: measure leaf temperature, air temperature, [RH](https://genetixbay.com/knowledge/glossary/relative-humidity.md) and [PPFD](https://genetixbay.com/knowledge/glossary/ppfd.md). Across the whole plant, with spotting or distorted growth, look at roots, calcium delivery and watering.

## Don't confuse with

- **Leaf clawing**: tips hook down, not edges up.
- **Praying leaves**: whole leaves angled upward but flat, a sign of a happy plant.
- **Broad mite damage**: twisted, glossy new growth.

## Related terms

[Heat stress](https://genetixbay.com/knowledge/glossary/heat-stress.md), [Light stress](https://genetixbay.com/knowledge/glossary/light-stress.md), [VPD](https://genetixbay.com/knowledge/glossary/vpd.md), [Leaf temperature](https://genetixbay.com/knowledge/glossary/leaf-temperature.md)

## Read more

- [Taco or canoeing leaves on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/taco-canoeing-leaves.md)
- [Heat and light stress: taco leaves, bleaching and foxtails](https://genetixbay.com/knowledge/environment/heat-light-stress.md)
- [Cannabis lookalike problems: how to tell them apart](https://genetixbay.com/knowledge/diagnosis/lookalikes.md)

## Sources

1. Nelson JA, Bugbee B, 2015. Analysis of environmental effects on leaf temperature under sunlight, HPS and LEDs. PLoS ONE 10(10): e0138930. https://pmc.ncbi.nlm.nih.gov/articles/PMC4598144/