Description

Oyster Shell Flour for Mushroom Substrate pH Buffering and Casing

Out-Grow's fine ground oyster shell flour is a natural calcium supplement and pH buffering agent widely used in mushroom cultivation. Its fine texture ensures uniform distribution throughout substrate blends, providing consistent calcium availability and stable pH levels that promote healthy mycelium development and robust fruiting.

Oyster shell flour is particularly valued as a casing substrate ingredient, where its neutral pH and mineral content create an ideal environment for pinning and fruiting in species like portobello and white button mushrooms. It performs equally well as a bulk substrate amendment, helping to stabilize pH in acidic substrate blends and providing essential calcium that supports cell wall development throughout the mushroom's growth cycle.

To use, incorporate oyster shell flour into your casing or bulk substrate at a 1:4 ratio by volume. No sterilization is required — simply mix thoroughly before use.

Beyond mushroom cultivation, oyster shell flour also serves as an effective soil amendment in gardening, raising soil pH and improving drainage in acidic or compacted soils.

Each bag contains 1lb of all-natural fine ground oyster shell flour with a long shelf life when stored in a cool, dry environment.