# Tissue test

> A tissue test is a lab analysis of dried leaf samples that measures the actual nutrient content of the plant, the most reliable way to confirm a deficiency or toxicity.

- Canonical: https://genetixbay.com/knowledge/glossary/tissue-test.html
- Also written: leaf tissue test, tissue analysis, plant tissue analysis, leaf analysis, foliar analysis
- Glossary category: Nutrients · 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"

A tissue test is a laboratory analysis of plant tissue, usually recently matured leaves, that reports the concentration of each nutrient: [macronutrients](https://genetixbay.com/knowledge/glossary/macronutrient.md) as percent of [dry weight](https://genetixbay.com/knowledge/glossary/dry-weight.md) and [micronutrients](https://genetixbay.com/knowledge/glossary/micronutrient.md) as mg/kg (ppm) of dry weight. Results are compared against sufficiency ranges for the crop.

## In practice

Sample the youngest fully expanded leaves (not the newest growth, not old [fan leaves](https://genetixbay.com/knowledge/glossary/fan-leaf.md)), from several plants of the same cultivar and stage, and send them clean and dry. Ranges depend on sampling position and stage, so follow the lab's or extension's protocol. NC State Extension publishes leaf-tissue reference ranges for floral [hemp](https://genetixbay.com/knowledge/glossary/hemp.md) (Suchoff and colleagues), which are a useful starting point for cannabis. A tissue test shows what the plant took up; a solution or [runoff](https://genetixbay.com/knowledge/glossary/runoff.md) test shows what was offered. Use both.

## Don't confuse with

- **Runoff test**: measures [EC](https://genetixbay.com/knowledge/glossary/ec.md) and [pH](https://genetixbay.com/knowledge/glossary/ph.md) of drainage, not plant content.
- **Water report**: analyses the source water.
- **Soil test**: measures what is in the soil, not what the plant absorbed.

## Related terms

[Nutrient deficiency](https://genetixbay.com/knowledge/glossary/nutrient-deficiency.md), [Nutrient toxicity](https://genetixbay.com/knowledge/glossary/nutrient-toxicity.md), [ppm of an element](https://genetixbay.com/knowledge/glossary/elemental-ppm.md)

## Read more

- [How to diagnose any cannabis plant problem](https://genetixbay.com/knowledge/diagnosis/how-to-diagnose-any-problem.md)

## Sources

1. Suchoff D, McGinnis M, Davis J, Whipker B, Hicks K. 2026. Hemp leaf tissue nutrient ranges: refinement of reference standards for floral hemp. NC State Extension AG-904. https://content.ces.ncsu.edu/hemp-leaf-tissue-nutrient-ranges
2. Cockson P, Landis H, Smith T, Hicks K, Whipker BE. 2019. Characterization of nutrient disorders of Cannabis sativa. Applied Sciences 9(20):4432. https://doi.org/10.3390/app9204432