Glass Jar Garden

Soils and layers

Horticultural sand as drawn in the simulator

Horticultural sand

Reusable

Coarse washed sand that opens soil and drains fast.

What the simulation uses

Holds water
10 % by volume
Water it keeps after draining; the rest runs down to the drainage.
Pore space
40 % by volume
Room for air and water between grains; low means roots suffocate when wet.
Weight
1440 g/L
How heavy a litre is.
pH
6.5 to 7.5 pH
How acid it keeps the soil.
Mould risk
none
How much fresh food it gives white mould; high-risk soils fuzz over in the first weeks.
Nutrients
none
Plant food it brings.
Presses down to
72 % of its loose depth
How far pressing can pack it, keeping its weight.

Description

Washed silica grains up to two millimetres across, heavy and free of nutrients. It suits arid mixes that need weight and drainage. Stirred into fine organic soil it can fill the air gaps instead, so keep the rest of the mix coarse.

Also called sharp sand, grit.

Estimated, where sources were thin: porosity/water values estimated from sand soil literature.

Sources

Grow it in a jar