Silicon is classed as a beneficial element: 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 in cell walls and around epidermal cells. Guerriero and colleagues identified transporter genes and silicon accumulation in cannabis tissue.
In practice
Growers add silicon mostly as potassium silicate, 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 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. It may reduce severity a little; it does not replace environment control and sanitation (Evidence: Supported for modest effect). See powdery mildew.
