Generic Horticultural Pumice 14 Dry Quarts - 3/8"–1/4" Particles for Cactus, Succulent & Bonsai Drainage

Lightweight volcanic pumice — 14 dry quarts of screened 3/8"–1/4" particles to improve drainage, aeration, and top-dressing for cacti, succulents, bonsai, and container mixes.

This bag contains naturally mined, dried, and screened pumice sized primarily between 3/8" and 1/4" (minimal fines), supplied as 14 dry quarts (approximately 3.5 gallons / 56 cups). Pumice is an inert, porous volcanic rock valued in horticulture for creating consistent air pockets, improving water flow through potting mixes, and providing a stable, erosion-resistant surface when used as top dressing. Because it is lightweight and won’t compact, pumice helps roots access oxygen while letting excess water drain away, making it especially useful for plants sensitive to overwatering.

How will this pumice change my soil’s drainage and aeration?

Adding pumice increases pore space in any potting medium so water moves through more freely while leaving room for air. Unlike heavier aggregates, pumice stays light and won’t settle into a dense layer, keeping the entire root zone well-aerated over time.

• Reduces waterlogging by improving percolation.
• Creates permanent air pockets for healthier root respiration.
• Resists compaction compared to finer soils or re-used potting mix.
• Maintains structure long-term without breaking down.

What’s the right way to mix and use pumice for succulents or bonsai?

Mix ratios depend on plant type: succulents and cacti typically need a gritty, fast-draining mix, while bonsai often benefit from blends that balance moisture retention and drainage. Pumice can be blended directly into potting soil or used as the primary inorganic component in a custom mix.

• Succulents/cacti: try 50–70% pumice with organic material for fast drainage.
• Bonsai: mix 30–60% pumice with akadama, grit, or composted bark as needed.
• Container plants: add 10–30% to improve soil structure and reduce compaction.
• Top dressing: spread a thin layer to reduce erosion and retain stable surface moisture.

Is this pumice different from perlite or pumice substitutes?

Pumice is a durable volcanic glass with a naturally rough surface and internal porosity, distinct from perlite’s lightweight, glassy beads. It provides long-lasting structure and often holds more moisture than perlite while still promoting drainage, making it a preferred choice for many growers.

• Pumice retains some moisture within pores yet drains well.
• Less likely to float or break down compared to perlite in outdoor mixes.
• Neutral and inert — won’t alter soil pH or nutrient balance.
• Provides weight and stability for top dressings and exposed roots.

How much pumice do I need per pot or bed?

Estimate by pot volume: 14 dry quarts covers small- to medium-sized collections and multiple repots. Use measurements and desired mix ratio to calculate required quantity before buying.

• Small 4" pots: roughly 1–2 cups per pot when used as a major mix component.
• 6–8" pots: typically 2–4 cups depending on mix percentage.
• Bonsai repots: a handful to a few quarts per specimen, depending on container size.
• Top dressing: a single bag covers several containers for a thin surface layer.

Who this is for: gardeners, hobbyists, and professional growers who need an inert, long-lasting aggregate to improve soil structure — especially owners of cacti, succulents, bonsai, orchids, and potted plants prone to overwatering. It’s a practical choice for repotting, custom potting mixes, surface top-dressing, and any application where improved drainage and aeration will benefit root health without adding weight or organic breakdown.