Soils and layers
Vermiculite
Golden flaky mineral that holds water and nutrients.
What the simulation uses
- Holds water
- 47.5 % by volume
- Water it keeps after draining; the rest runs down to the drainage.
- Pore space
- 85 % by volume
- Room for air and water between grains; low means roots suffocate when wet.
- Weight
- 97.5 g/L
- How heavy a litre is.
- pH
- 6 to 8 pH
- How acid it keeps the soil.
- Mould risk
- low
- How much fresh food it gives white mould; high-risk soils fuzz over in the first weeks.
- Nutrients
- low
- Plant food it brings.
- Presses down to
- 72 % of its loose depth
- How far pressing can pack it, keeping its weight.
Description
Flaky mica-like mineral that holds far more water than perlite and adds a little potassium and magnesium. It squashes down over time, so wet layers turn soggy. Avoid very old stock, which may contain asbestos.
Also called exfoliated vermiculite.
Estimated, where sources were thin: water holding and AFP estimated; pH varies 6-9 by source.