# Root zone

> The root zone is the volume of medium or solution where a plant's roots live, including its water, air, temperature, pH, EC and microbes.

- Canonical: https://genetixbay.com/knowledge/glossary/root-zone.html
- Also written: root environment, rootzone, root-zone conditions, below-ground
- Glossary category: Systems and media · 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 root zone is everything around the roots: the medium or solution, its moisture and air, its temperature, its [pH](https://genetixbay.com/knowledge/glossary/ph.md) and nutrient concentration ([EC](https://genetixbay.com/knowledge/glossary/ec.md)), and the microbes living on and around the roots. The [rhizosphere](https://genetixbay.com/knowledge/glossary/rhizosphere.md), strictly, is the thin layer of soil directly influenced by root secretions, where microbial activity is highest.

## In practice

Most "nutrient" problems start in the root zone. The diagnostic order GenetixBay teaches is: check root-zone pH and EC, moisture and oxygen, and root health before blaming a [deficiency](https://genetixbay.com/knowledge/glossary/nutrient-deficiency.md). Typical targets: pH about 6.0-7.0 in soil and 5.5-6.5 in [soilless](https://genetixbay.com/knowledge/glossary/soilless.md) and hydro; root-zone temperature about 18-24 °C (64-75 °F); a medium that is moist with plenty of air, or a solution with high dissolved oxygen. Healthy roots are white to cream and smell earthy; brown, slimy or sour-smelling roots point to rot.

## Don't confuse with

- **Growing medium**: the material; the root zone is the whole environment.
- **Canopy**: the above-ground environment of leaves and buds.

## Related terms

[Growing medium](https://genetixbay.com/knowledge/glossary/growing-medium.md), [Dissolved oxygen](https://genetixbay.com/knowledge/glossary/dissolved-oxygen.md), [Air-filled porosity](https://genetixbay.com/knowledge/glossary/air-filled-porosity.md), [Mycorrhizae](https://genetixbay.com/knowledge/glossary/mycorrhizae.md), [Root rot](https://genetixbay.com/knowledge/glossary/root-rot.md)

## Read more

- [How to diagnose any cannabis plant problem](https://genetixbay.com/knowledge/diagnosis/how-to-diagnose-any-problem.md)
- [Brown roots in hydroponics (DWC, RDWC, NFT): a differential](https://genetixbay.com/knowledge/diagnosis/root-browning-hydro.md)

## Sources

1. Raviv M, Lieth JH, Bar-Tal A (eds), 2019. Soilless Culture: Theory and Practice, 2nd ed. Elsevier. https://doi.org/10.1016/C2015-0-01807-5