---
title: Orchid bark in a terrarium | Glass Jar Garden
description: Orchid bark (fir/pine bark): Chunky bark chips that keep a mix open and airy. In the jar it has holds water 30 % by volume, pore space 80 % by volume, weight...
url: https://glassjar.garden/guide/soils/orchid-bark/
---

Soils and layers

# Orchid bark (fir/pine bark)

Chunky bark chips that keep a mix open and airy.

## What the simulation uses

- Holds water: 30 % by volume (Water it keeps after draining; the rest runs down to the drainage.)

- Pore space: 80 % by volume (Room for air and water between grains; low means roots suffocate when wet.)

- Weight: 240 g/L (How heavy a litre is.)

- pH: 4 to 5.5 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.)

- Breaks down in: 2 to 5 years (How long it lasts before rotting down to fine soil.)

- Nutrients: low (Plant food it brings.)

- Presses down to: 72 % of its loose depth (How far pressing can pack it, keeping its weight.)

## Description
Fir or pine bark chips, acidic and slow to rot thanks to their tannins. It is a classic medium for epiphytes. Fresh bark can feed a white mould bloom, and over two to five years it crumbles into fines.

Also called pine bark, fir bark, bark chips.

Estimated, where sources were thin: porosity/AFP/pH/CEC from recalled Pine bark literature, not fetched.

## Sources

- [en.wikipedia.org/wiki/Bark_(botany)](https://en.wikipedia.org/wiki/Bark_(botany))
- [engineeringtoolbox.com/density-materials-d_1652.html](https://www.engineeringtoolbox.com/density-materials-d_1652.html)

[Grow it in a jar](https://glassjar.garden/?guide=soils/orchid-bark)

[Oak leaf litter](https://glassjar.garden/guide/soils/oak-leaves/) · [Pea gravel](https://glassjar.garden/guide/soils/pea-gravel/) · [All soils and layers](https://glassjar.garden/guide/soils/)