---
title: Coco coir in a terrarium | Glass Jar Garden
description: Coco coir: Soft brown coconut fibre that soaks up water like a sponge. In the jar it has holds water 70 % by volume, pore space 93 % by volume, weight 70 g/L.
url: https://glassjar.garden/guide/soils/coco-coir/
---

Soils and layers

# Coco coir

Soft brown coconut fibre that soaks up water like a sponge.

## What the simulation uses

- Holds water: 70 % by volume (Water it keeps after draining; the rest runs down to the drainage.)

- Pore space: 93 % by volume (Room for air and water between grains; low means roots suffocate when wet.)

- Weight: 70 g/L (How heavy a litre is.)

- pH: 5.4 to 6.8 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: 3 to 6 years (How long it lasts before rotting down to fine soil.)

- Nutrients: low (Plant food it brings.)

- Presses down to: 40 % of its loose depth (How far pressing can pack it, keeping its weight.)

## Description
Made from coconut husk, it holds water like a sponge and takes years to break down. Dry bricks swell four to six times when soaked. Keep it from staying soggy, since overwet coir is prone to mould and yellow mushrooms.

Also called coconut fibre, coco husk, coir pith, coco peat.

Estimated, where sources were thin: numeric BD/porosity/pH/CEC from Evans et al. 1996 HortScience not readable (paywall JS); values estimated from recalled literature.

## Sources

- [en.wikipedia.org/wiki/Coir](https://en.wikipedia.org/wiki/Coir)
- [en.wikipedia.org/wiki/Hydroponics](https://en.wikipedia.org/wiki/Hydroponics)
- [joshsfrogs.com/sp/josh-s-frogs-coco-husk-block-4-5-kg-38-quarts-jfd58082](https://joshsfrogs.com/sp/josh-s-frogs-coco-husk-block-4-5-kg-38-quarts-jfd58082)

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

[Clay](https://glassjar.garden/guide/soils/clay/) · [Coco husk chips](https://glassjar.garden/guide/soils/coco-husk-chips/) · [All soils and layers](https://glassjar.garden/guide/soils/)