# Sulfur

> Sulfur (S) is a secondary nutrient taken up as sulfate, used in the amino acids cysteine and methionine; deficiency yellows new growth fairly evenly.

- Canonical: https://genetixbay.com/knowledge/glossary/sulfur.html
- Also written: S, sulphur, sulfur deficiency, sulphur deficiency
- 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"

Sulfur is a secondary macronutrient absorbed as the [sulfate ion](https://genetixbay.com/knowledge/glossary/sulfate.md) (SO4 2-). It is built into the amino acids cysteine and methionine, into coenzymes and into many defence compounds. It is only partly mobile, so [deficiency](https://genetixbay.com/knowledge/glossary/nutrient-deficiency.md) tends to show on younger leaves first.

## In practice

A sulfur-short plant looks like it lacks nitrogen, but the even pale yellowing starts on new or middle growth rather than the bottom leaves. True deficiency is uncommon in hydro, because [magnesium sulfate](https://genetixbay.com/knowledge/glossary/magnesium-sulfate.md) and [potassium sulfate](https://genetixbay.com/knowledge/glossary/potassium-sulfate.md) bring plenty of S along. Feeds typically land somewhere around 50-100 mg/L (ppm) S, and plants tolerate a wide range.

## Don't confuse with

- **Sulfur burner or elemental sulfur sprays**: used against mildew, not as a feed.
- **Nitrogen deficiency**: starts on old leaves; sulfur deficiency starts higher up.
- **Volatile sulfur compounds**: the skunky aroma molecules in cannabis contain sulfur, but feeding more S has not been shown to raise them.

## Myth check

"More sulfur makes buds smell stronger" has no controlled support (Evidence: Myth until tested). The plant needs adequate S; extra sulfate mostly raises [EC](https://genetixbay.com/knowledge/glossary/ec.md). See [Mythbusters](https://genetixbay.com/knowledge/mythbusters.md).

## Related terms

[Sulfate](https://genetixbay.com/knowledge/glossary/sulfate.md), [Secondary nutrient](https://genetixbay.com/knowledge/glossary/secondary-nutrient.md), [Magnesium sulfate](https://genetixbay.com/knowledge/glossary/magnesium-sulfate.md), [Potassium sulfate](https://genetixbay.com/knowledge/glossary/potassium-sulfate.md), [Nitrogen](https://genetixbay.com/knowledge/glossary/nitrogen.md)

## Read more

- [Sulfur (S) in cannabis: role, deficiency, targets and sulfate sources](https://genetixbay.com/knowledge/nutrients/sulfur.md)

## Sources

1. Marschner P (ed.). 2012. Marschner's Mineral Nutrition of Higher Plants, 3rd ed. Academic Press. https://doi.org/10.1016/C2009-0-63043-9
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