Pumice

Pumice is a durable, porous mineral amendment. It adds weight and longer-lasting open texture to potting mixes.

• Main use: Blend into cactus, succulent, bonsai and suitably open tropical growing media.
• Texture: Porous particles provide air spaces and some internal moisture-holding capacity.
• Preparation: Rinse loose mineral dust if necessary before use.
• Proportion: Adjust to root size, particle grading, container and drying conditions. Avoid a universal fixed percentage.
• Nutrition: Mineral pumice is not a complete fertiliser.
• Safety: Do not allow pets or children to ingest loose mineral particles.

• As a drainage additive: mix 10–30 % pumice into potting soil to improve aeration and drainage for cacti, succulents, bonsai and dry-tolerant aroids.
• Mineral-heavy mixes: combine pumice with sand and a small amount of organic material for very fast-drying substrates (for example Lithops or other mesembs).
• Top dressing: apply a thin layer of pumice on the soil surface to reduce splashing and keep crowns slightly drier.
• Terrariums and rocky plantings: use pumice to create natural-looking, rocky areas with good drainage and a textured appearance.
• Root training for bonsai: include a high share of pumice in bonsai soils to support fine root development and stable moisture without waterlogging.
• Handling tip: rinse the material before use if needed to remove loose dust.

• Compared with perlite: pumice is heavier and more stable, less likely to float to the surface and better for outdoor containers or taller pots.
• Structure: Pumice improves drainage and aeration while still adding weight and structure.
• For very arid plants: increase pumice content and reduce water-retentive components so pots dry fully between thorough waterings.
• For indoor aroids: adding a modest share of pumice to coco- and bark-based mixes improves structure without pushing them into full “succulent soil” territory.
• Blending with other minerals: pumice pairs well with perlite, lava gravel and horticultural sand to fine-tune weight, drainage speed and appearance.