# Soilless

> A soilless medium contains no mineral soil, such as peat, coco, rockwool or perlite blends, and relies mostly on the grower to supply nutrients.

- Canonical: https://genetixbay.com/knowledge/glossary/soilless.html
- Also written: soilless mix, soilless medium, soilless growing, soil-less, inert medium
- 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"

Soilless growing uses a substrate with no mineral soil in it. Common soilless media are peat moss blends, [coco coir](https://genetixbay.com/knowledge/glossary/coco-coir.md), [rockwool](https://genetixbay.com/knowledge/glossary/rockwool.md), [perlite](https://genetixbay.com/knowledge/glossary/perlite.md), pumice, bark and [clay pebbles](https://genetixbay.com/knowledge/glossary/clay-pebbles.md), used alone or mixed. Some (peat, coco) have a [cation exchange capacity](https://genetixbay.com/knowledge/glossary/cation-exchange-capacity.md) and hold nutrients; others (rockwool, perlite, clay) are nearly inert.

## In practice

Soilless media are lighter, cleaner and more consistent than garden soil and are free of most soil pests. They are fed with nutrient solution, usually at every watering or nearly so, at a [pH](https://genetixbay.com/knowledge/glossary/ph.md) of about 5.5-6.5. Most "[potting soil](https://genetixbay.com/knowledge/glossary/potting-mix.md)" sold in bags is actually a soilless peat or coco mix with lime and a starter charge of fertiliser that runs out in a few weeks.

[Air-filled porosity](https://genetixbay.com/knowledge/glossary/air-filled-porosity.md), how much of the pot is air after drainage, matters more than which material is used.

## Don't confuse with

- **Hydroponics**: often overlaps; soilless media fed with mineral solution are frequently called hydro.
- **Soil**: contains mineral particles and, in living soil, a managed microbial population.

## Related terms

[Hydroponics](https://genetixbay.com/knowledge/glossary/hydroponics.md), [Coco coir](https://genetixbay.com/knowledge/glossary/coco-coir.md), [Peat](https://genetixbay.com/knowledge/glossary/peat.md), [Rockwool](https://genetixbay.com/knowledge/glossary/rockwool.md), [Growing medium](https://genetixbay.com/knowledge/glossary/growing-medium.md)

## Read more

- [Growing in coco coir](https://genetixbay.com/knowledge/systems/coco.md)
- [Choosing your growing system: soil, coco, rockwool or hydro](https://genetixbay.com/knowledge/systems/choosing-a-system.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