I have tried growing mushrooms using the pre-packaged, pre-inoculated blocks of sawdust-like material that you can find in plant shops and grocery stores. I’ve even written about here within PlantersPlace.com. I’ll be honest—I didn’t have a whole lot of success. Was it me? Was it a faulty mushroom block? Several faulty mushroom blocks? Not being sure, I chose to let the professionals handle the process and to limit my mushroom acquisition to the market.

When I saw a recent a notice for a local workshop on DIY mushroom growing using logs, I decided I did indeed need to get schooled on the mushroom-growing process. The 2-hour class was sporulating with great information on the topic (a little mushroom humor). With that the case, I’ve decided to break up this topic into several separate posts.

Two Key Tenets

Before starting on the meat of the growing procedures, our instructor emphasized these two points:

• Dry logs will kill your mushrooms
• Mushrooms grown on logs taste better

The first is fact. Mushrooms are living organisms, even if you can’t see the spore, germ and hyphal phases of their lifecycle. They need moisture to spread their spores and extend through a growing medium—i.e. the log. Of course your logs have to be moist!

The second is subjective, of course. Maybe mushrooms grown on logs taste better because you grew them yourself. Like the teeny tiny fish you caught tastes better than any other fish you’ve eaten (or is that just me?).

Our instructor broke down the mushroom-growing process into four phases. Let’s begin at the beginning, which he labeled as Substrate Acquisition.

What to Look For When Choosing Mushroom Logs

Find fresh, live wood. Typically this means tree logs about 3-4 ft. long and a diameter of 4-8 in. in diameter. And by “fresh” he means logs that were cut 2-6 weeks prior. Why not something that’s been lying in your back yard since a storm 6 months ago? Because that wood may already have living spores inside. You want to be sure only the mushrooms you inoculate the log with are the ones that will grow. Also, the smaller the diameter, the faster the log will dry out. And as he mentioned, dry logs will kill your mushrooms.

Oak, sugar maple and poplar are the best woods to use. Fruit tree wood isn’t recommended, and he wasn’t sure but speculated the wood for fruit trees might be less dense.

Don’t use black walnut and black locust. Both have naturally occurring chemicals that discourage fungal growth.

Wood density is important. This relates to the log’s moisture content. The less dense the wood, the faster the log dries out, and “moisture management” is key, he kept reiterating during the workshop. The instructor said that looser wood also breaks down faster, so your mushroom logs won’t last as long. Denser wood holds moisture better.

Cut wood for mushroom logs before sap rises. Once the sap starts to flow upward, this increases the chance of the bark being slippery in between the bark and the wood. This will eventually lead to logs that dry out faster.

Log placement. Even before you inoculate your logs you need to find a spot that has year-round shade, so the logs don’t dry out from being in the sun. Under evergreens is a good option since they have shade under them year round. The logs should also have as little contact with the soil as possible. This prevents bugs from burrowing into the wood.

Next time, I’ll discuss the inoculation process. Meanwhile, if you’re serious about growing mushrooms on logs, head out to your wooded lot or find a neighbor with some wood and start searching for some fresh, relatively straight logs to become your mushrooms’ future homes.