Sawdust & Plug Spawn FAQ

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 an inoculation tool is required, along with other tools if 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.

Logs should be inoculated within a week or two of cutting. This allows the cells in the tree to die but is not long enough for the log to dry out or for other competitor fungi to become established. You should not use logs that were cut last year or logs with damaged bark. A month would be about the longest reasonable stretch of time between cutting and inoculating.

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.

Plug and sawdust spawn will store for six months to a year in a refrigerator. The fresher the better, but mycelium is pretty resilient. If you don’t get around to inoculating right away, tuck it away in your refrigerator until you’re ready.

Mushroom spawn will naturally develop a layer of white mycelium (or yellow for Chicken of the Woods). This is totally normal and indicates healthy spawn. Break up your spawn bags thoroughly before use. And be sure to use logs cut within 4 weeks of inoculation.

No, the Wine Cap only grows on substrate that is already broken apart, like sawdust. It's best in garden path areas or other places where beds of sawdust, wood chips or straw can be maintained.

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.

Store the spawn in the fridge until you’re ready. We recommend waiting no more than a few months. Just be sure to inoculate your logs within 4 weeks of cutting them. We recommend avoiding log harvest in the spring between bud well and full-leaf out, since nutrients are directed toward flower and foliage growth and bark is loose. See our section about best time to harvest logs for more info.

Mushroom spawn will naturally develop a white (or yellow for Chicken of the Woods), mold-like layer called mycelium. This branching network of threads is the primary body of fungi, the vegetative structure. A good analogy is if a mushroom is like an apple, then mycelium is like an apple tree. Seeing mycelium grow through your bag is normal and indicates healthy mushroom spawn. If your spawn looks green or black, the culture may be contaminated and should be discarded. You can reach out to us for confirmation.

In the following images, you’ll see healthy spawn plugs with different amounts of mushroom culture visible. The first photo shows plugs with minimal mycelial growth. They are completely fine to use and not any less 'potent'. Over time the mycelium will continue to grow and envelop the plugs as seen in the second photograph. This is also normal and doesn't change how the plugs are used, though you may need to break up the plugs within the bag before use to separate them from the mycelial mass. Don't open the bag; simply squeeze it to break up the mycelial mass. The third photo is the same plug bag after it has been broken.

Often, mycelium is broken up in shipping, so it can appear less myceliated. Let it sit for a few days and it should bounce back.

Millet! We grow out our mushroom cultures on a mix of nutrient-rich grains to help them transfer onto wood. They are totally normal and can be ignored in your inoculation process.