---
title: Pine bark fines in a terrarium | Glass Jar Garden
description: Pine bark fines: Small pieces of pine bark that keep soil open and airy. In the jar it has holds water 37.5 % by volume, pore space 77.5 % by volume, weight...
url: https://glassjar.garden/guide/soils/pine-bark-fines/
---

Soils and layers

# Pine bark fines

Small pieces of pine bark that keep soil open and airy.

## What the simulation uses

- Holds water: 37.5 % by volume (Water it keeps after draining; the rest runs down to the drainage.)

- Pore space: 77.5 % by volume (Room for air and water between grains; low means roots suffocate when wet.)

- Weight: 275 g/L (How heavy a litre is.)

- pH: 4.5 to 5.5 pH (How acid it keeps the soil.)

- Mould risk: medium (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
Small pieces of pine bark that keep soil open and airy. They are acidic and slow to rot, lasting two to five years. Fresh bark can fuel a mould bloom.

Also called fine bark, bark mulch.

Estimated, where sources were thin: values estimated from hobby and horticultural references; not measured.

See also: [Terrarium layers explained](https://glassjar.garden/guide/terrarium-layers/) · [Terrarium drainage: LECA vs gravel vs lava rock](https://glassjar.garden/guide/drainage-leca-vs-gravel/).

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

[Perlite](https://glassjar.garden/guide/soils/perlite/) · [Pumice](https://glassjar.garden/guide/soils/pumice/) · [All soils and layers](https://glassjar.garden/guide/soils/)