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Mushroom Plug Spawn

Plug spawn is hardwood dowels infused with live mushroom mycelium, making it one of the easiest and most reliable ways to grow gourmet mushrooms on logs. Simply drill, tap, and seal. Let nature do the rest!

Skill Level

Frequently Asked Questions

Plugs are very resilient but are slower to colonize. Plugs require only a drill and hammer for tools, and are economical for smaller projects. Sawdust colonizes drilled logs about 30% faster than plugs. They're good for larger projects, but aninoculation toolis required, along withother toolsif you'd like to speed up the project. The totem method, using sawdust, is good for urban settings or other locations without access to a forested or shady area. No special tools are needed.

You can use this log inoculation calculator to help you figure out exactly how much spawn you'd need, depending on the size of the log and hole spacing.For the totem method, one 5 lb. bag of sawdust spawn should be enough to inoculate three or four 10-12" stacks.

The general rule of thumb is one year of production per inch of log diameter. However, yields will vary greatly depending on the mushroom strain, tree species used, and environmental conditions each season.

Shiitake logs usually have their largest flushes during their second and third years producing. A good yield per log is ¼ - ½ pound each flush, with 2-3 flushes per season.

For plug spawn, you’ll need a drill with a 5/16” (8mm) bit to make holes in the log, a hammer to drive the plugs into the holes and wax to seal the holes. If you are inoculating several logs, you may find that an angle grinder adapter with an 8.5mm drill bit will help the work to go more quickly.

For sawdust spawn, we recommend a drill with a 7/16” (12mm) drill bit and an inoculation tool to pack the sawdust into the holes. If you are inoculating several logs, you may find that an angle grinder adapter with an 12mm drill bit will help the work to go more quickly. You can insert sawdust into the holes by hand but an inoculation tool greatly speeds up the process and allows the sawdust to be packed more densely increasing the success of log inoculations.

All of the holes need to be sealed with hot wax (cheese wax, food grade paraffin wax, beeswax etc…) to prevent them from drying out and to seal them off from contamination.

That will depend on what species you’re growing, the size of your logs, and environmental conditions. Most mushrooms on standard size logs in temperate climates will take about a year to fully colonize before they fruit. This can vary between 6 months to two years. Smaller diameter logs and soft hardwoods will typically fruit sooner, though they’ll have less longevity.

Often, mushrooms need cool weather and moisture to fruit. Growth slows in the heat of the summer. If you inoculate in the spring, you might get your first flush of mushrooms in the fall but most likely it will take a full year until you see your first fruiting. If you inoculate in the fall and are able to keep the mycelium from going dormant, you may get mushrooms as soon as the next spring, though more likely the following fall.

A cluster of brown-capped mushrooms with long, pale stems against a plain white background.