Premium Grade Horticultural Pumice 2L 1-2 mm

Pumice is a light, porous volcanic rock that forms during explosive eruptions. It resembles a sponge because it consists of a network of gas bubbles frozen amidst fragile volcanic glass and minerals. All types of magma (basalt, andesite, dacite, and rhyolite) will form pumice.

Here’s a clear summary of what you provided, organized for easy understanding:

What is Pumice?

Pumice is a lightweight, foamy volcanic rock formed when lava cools rapidly and depressurizes, trapping bubbles within the rock. Key characteristics include:

• Lightweight and hard compared to other aggregates.

• Highly porous, allowing roots to access both air and water efficiently.

• High surface area, promoting strong root anchorage.

• Mined in the North Island of New Zealand, near Lake Taupo.

Pumice Grades

• 1–2 mm – Very fine, used for propagation of cuttings.

• 1–7 mm – Fine, also for propagation and slow-rooting species.

• 4–20 mm – Medium coarse, general use in mixes.

• 7–20 mm – Coarse, ideal for orchids and mixes needing drainage and aeration.

Usage

• Orchid mixes – Use 7–20 mm grade for long-lasting, well-draining substrate.

• Propagation – Use 1–2 mm or 1–7 mm for hardwood cuttings, slow-rooting species (Conifers, Maples, Camellias).

• Cacti & Succulents – Mix 30% pumice with organic substrates for well-draining potting mix.

• Green roofs – Provides lightweight, free-draining, and moisture-retentive substrate.

• Long-life potting mixes – Maintains structure without rotting or washing out.

Ideal For

• Orchids

• Cacti and Succulents

• Bonsai

• Propagation of cuttings

• Green roofs

• Long-life potting mixes

Properties

• Lightweight

• Up to 90% porosity

• Chemically inert

• Clean and mineral-based

• High capillary action (retains water well)

• Low cation exchange rate (minimal nutrient binding)