VanSil Wollastonite — Natural Calcium Silicate Fertilizer
VanSil wollastonite by Vanderbilt Minerals is the only OMRI-certified wollastonite mined and milled entirely in the USA — sourced from Lewis County, New York. Not a slag byproduct. The 4 lb size is ideal for home gardeners, container growers, and small greenhouse operations looking to incorporate silicon and calcium into their programs on a regular basis.
Use as a gentle lime alternative to raise media pH while delivering plant-available silicon (Si) and carbon-neutral calcium (Ca) to your root zone. Silicon strengthens cell walls, improves stress and pest tolerance, and enhances overall plant vigor without the pH spike risk of hydrated lime.
Guaranteed Analysis
- CaO: 45% | Ca: 34%
- SiO₂: 50% | Total Si: 24% | Soluble Si: 3.6%
Key Benefits
- Plant-available silicon — strengthens cell walls; improves stress and pest tolerance
- Gentle pH correction — raises media pH without the spike risk of hydrated lime
- Carbon-neutral calcium — no heavy metals, no slag
- OMRI Listed — certified for organic production under the NOP
- USA mined & milled — the only OMRI-certified wollastonite sourced entirely in the USA
- 4 lb bag — ideal for home gardens, container programs, and small greenhouse operations
State restrictions: Not available for shipment to Oregon.
- Easy to use: Use as an alternative to lime and to provide Plant Available Silicon and Calcium in your soilless potting mixes.
- High Analysis: 34% calcium and 24% silicon
- OMRI Listed: The only OMRI certified wollastonite mined and milled in the United States.
- Pure: Low in heavy metals, sodium and chloride.
Typical Chemical Analysis (calculated as oxides)
| Calcium Oxide (CaO) 45% | Calcium (Ca) 34% |
| Silicon Dioxide (SiO2) 50% | Total Silicon (Si) 24% |
| Aluminum Oxide (Al2O3) 0.7% | Magnesium Oxide (MgO) 1.5% |
| Iron Oxide (Fe2O3) 0.2% | Sodium Oxide (Na2O) <0.1% |
| Manganese Oxide (MnO) <0.1% | pH of a 10% slurry 10-11 |
VanSil Wollastonite Calcium Silicate 4 lb
VanSil Wollastonite Calcium Silicate 4 lb
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