Coarse Pumice 1/4"-3/8" by The Bonsai Supply - 20 Quarts

Build stronger root systems and improve soil performance with Coarse Pumice by The Bonsai Supply. Carefully screened to a particle size of 1/4"–3/8", this premium horticultural pumice provides an ideal balance of moisture retention, drainage, and aeration, making it one of the most valuable components in modern bonsai soil mixes.

Unlike heavier substrates, pumice is highly porous and lightweight, allowing it to absorb water and nutrients while still maintaining the air spaces roots need for vigorous growth. The coarse particle size makes this grade particularly well suited for larger bonsai, development projects, pond baskets, grow boxes, and fast-draining soil blends.

Whether used as a standalone growing medium or blended with akadama, lava rock, or other substrates, pumice remains one of the most versatile and widely used ingredients in bonsai cultivation.

Features

• Premium horticultural pumice screened for bonsai use
• Excellent balance of moisture retention and drainage
• Highly porous structure improves oxygen availability to roots
• Lightweight material reduces overall pot weight
• Maintains soil structure and resists compaction
• Reusable after proper cleaning and screening

Ideal For

• Custom bonsai soil blends
• Junipers and conifers
• Development material
• Pond baskets and grow containers
• Larger bonsai trees
• Increasing water retention in fast-draining mixes

Specifications

• Brand: The Bonsai Supply
• Product Type: Horticultural pumice
• Particle Size: 1/4"–3/8"
• Grade: Coarse
• Volume: 20 Quarts
• Use: Soil component and root development
• Suitable For: Bonsai soil blends and development projects

Few soil components contribute as much to root health as quality pumice, providing the moisture balance, aeration, and durability needed to support strong growth and healthy bonsai for years to come.