# Silicon

> Silicon (Si) is a beneficial element, not strictly essential, that plants absorb as silicic acid and deposit in cell walls, stiffening tissue and aiding stress tolerance.

- Canonical: https://genetixbay.com/knowledge/glossary/silicon.html
- Also written: Si, silicic acid, monosilicic acid, orthosilicic acid
- Glossary category: Nutrients · 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"

Silicon is classed as a [beneficial element](https://genetixbay.com/knowledge/glossary/beneficial-element.md): most plants complete their life cycle without it, but many perform better with it. Roots absorb it as uncharged monosilicic acid, and it is deposited as amorphous [silica](https://genetixbay.com/knowledge/glossary/silica.md) in cell walls and around epidermal cells. Guerriero and colleagues identified transporter [genes](https://genetixbay.com/knowledge/glossary/gene.md) and silicon accumulation in cannabis tissue.

## In practice

Growers add silicon mostly as [potassium silicate](https://genetixbay.com/knowledge/glossary/potassium-silicate.md), for stiffer stems and better tolerance of heat, salt and some fungal pressure. Evidence for disease suppression is strongest in high-silicon accumulators such as grasses; cannabis is a moderate accumulator, so expect modest effects. Silicate products are strongly alkaline and must go into the water first, before other nutrients, then [pH](https://genetixbay.com/knowledge/glossary/ph.md) is adjusted.

## Don't confuse with

- **Silica**: silicon dioxide, the solid form; growers often say "silica" for any silicon supplement.
- **Silicone**: a synthetic polymer, unrelated to nutrition.
- **Silicate**: the anion in silicate salts, which converts to silicic acid in solution.

## Myth check

Silicon is not a cure for [powdery mildew](https://genetixbay.com/knowledge/glossary/powdery-mildew.md). It may reduce severity a little; it does not replace environment control and sanitation (Evidence: Supported for modest effect). See [powdery mildew](https://genetixbay.com/knowledge/diseases/powdery-mildew.md).

## Related terms

[Silica](https://genetixbay.com/knowledge/glossary/silica.md), [Potassium silicate](https://genetixbay.com/knowledge/glossary/potassium-silicate.md), [Beneficial element](https://genetixbay.com/knowledge/glossary/beneficial-element.md), [Micronutrient](https://genetixbay.com/knowledge/glossary/micronutrient.md)

## Read more

- [Silicon (Si) for cannabis: beneficial, not essential, and how to dose it](https://genetixbay.com/knowledge/nutrients/silicon.md)

## Sources

1. Epstein E. 1994. The anomaly of silicon in plant biology. PNAS 91(1):11-17. https://doi.org/10.1073/pnas.91.1.11
2. Guerriero G, Deshmukh R, Sonah H, Sergeant K, Hausman JF, Lentzen E, Valle N, Siddiqui KS, Exley C. 2019. Identification of the aquaporin gene family in Cannabis sativa and evidence for the accumulation of silicon in its tissues. Plant Science 287:110167. https://doi.org/10.1016/j.plantsci.2019.110167
3. Fauteux F, Remus-Borel W, Menzies JG, Belanger RR. 2005. Silicon and plant disease resistance against pathogenic fungi. FEMS Microbiology Letters 249(1):1-6. https://doi.org/10.1016/j.femsle.2005.06.034