Sawdust spawn is sterilized sawdust colonized with mushroom mycelium. It’s used to inoculate a growing substrate such as logs, wood chips, or outdoor garden beds to start mushroom growth.

It serves as the "seed" for your mushroom crop — transferring live, growing mycelium into your chosen growing medium.

Sawdust spawn is best for outdoor projects like logs, stumps, or garden beds and is slower to contaminate.
Grain spawn is ideal for indoor grows or bulk substrate inoculation because it colonizes faster but is more contamination-sensitive.

Sawdust spawn is mixed or packed into a substrate (like logs or wood chips) to inoculate it. Common methods include:

• Drilling and filling holes in logs
• Layering in outdoor wood chip or straw beds
• Mixing with sterilized sawdust or wood pellets for bag cultivation

Most sawdust spawn performs best on hardwoods like oak, maple, or beech. Some species (like Wine Cap or certain Oysters) can tolerate small amounts of softwood in the mix.