Make a Gourmet Mushroom Fruiting Log
Have you ever wondered how to grow gourmet mushrooms on logs? With Forest Fungi inoculated dowels and grain spawn, Shiitake log cultivation is very easy to do, low maintenance and incredibly rewarding. You don't need large sheds and lots of technical expertise and equipment to grow gourmet mushrooms. With log cultivation, anyone can grow mushrooms, even in a small apartment with little space. Below you will find six simple steps to growing gourmet mushrooms on logs. Shiitake are the commonly grown mushroom on logs, however you can also grow other varieties such as Reishi, Pioppinos, Nameko, and most Oyster mushrooms.
- Hardwood log
- Optional - Angle grinder and adapter or high speed drill
- Forest Fungi inoculated dowels or grain spawn
- Bees wax or cheese wax
- Something to apply wax with i.e. paintbrush
- Shady position or a piece of shade cloth
STEP 1: Sourcing your hardwood log
So, broadly speaking, we want Broad leaved trees. Or to put it another way, we want Hardwoods, which are flowering trees (angiosperms), as opposed to softwoods (gymnosperms). These terms don’t refer to how hard or soft the wood actually is. There are, of course, mushrooms that will grow on conifers and other softwoods.Not all hardwoods are good for mushrooms. If you think of rot resistant woods, they manage to resist fungal decay because they contain anti-fungal resins, so are best avoided. Species Forest Fungi has used successfully include all the Eucalyptus we’ve tried and various Oaks. Others use Poplars, Willows, Alder, Birch, Wattles….there is a big list in Stamets book, Growing Gourmet and Medicinal Mushrooms, 2000, 48 - 49.
STEP 2: Chopping down your selected tree
After we choose our tree, we need to chop it down. This can be done at any time, however many people prefer to chop in winter and spring. This is partly because deciduous trees have shed their leaves, so it’s easier to work in the forest (not so relevant in Australia). The important thing is that your logs have a good amount of sapwood, as this is generally what our mushrooms will eat. The heartwood is the wood at the centre of the log, and our mushrooms struggle to digest it. As for bark, many people prefer bark that stays on the wood for a long time, as this can conserve moisture and protect the mycelium. I have fruited logs with no bark, thin bark, thick bark...as long as you keep the logs from drying out, they should be fine. It is best to let your log rest for at least two weeks before inoculating, to allow the antifungals in the wood to dissipate. Logs can be rested for several months before inoculating but the longer you wait the higher the likelihood that other fungi will start to grow in the wood.
STEP 3: Drilling holes into your log
You now need to drill holes into your log to place the inoculated dowel or grain spawn into. We have found using an angle grinder adapter the quickest and easiest method to use. Drill holes around your log - the science behind this is not too technical. You may wish to space drill holes around 10 - 15cm apart. Our practice is to heavily inoculate both ends with less inoculation in the middle of the log. the more mycelium you add, the faster the colonisation. Chainsaws can also be used to cut notches into logs, which can then be filled with sawdust spawn.
STEP 4: Inoculating your log with dowels or grain spawn
The next step is to introduce some mycelium into the wood. This can be achieved in many ways, most commonly it involves filling the hole with dowel spawn or grain spawn.
If you are using inoculated dowels, simply fill each drilled hole with an inoculated dowel - using a mallet to drive the inoculated dowels in if required.
If you are using grain spawn, use a sawdust spawn inoculator and fill each drilled hole with your grain spawn.
STEP 5: Protecting the mycelium
We now have to protect the exposed mycelium from drying out and from pests. Usually wax, such as beeswax or cheese wax is melted, then dabbed over the hole that is filled with dowel or grain spawn.
STEP 6: Caring for your log
Now your logs have been inoculated, you need to keep them somewhere….I like to think about the mushrooms natural habitat, then try and emulate it. For Shiitake, and indeed most species, the forest is their natural habitat. I like to provide shade, (under a tree, in the garage, even shade cloth), moisture (we nee to prevent the logs from drying out), and when they start fruiting, protection from pests such as rats. We have logs sitting by the dam where it is shady and moist. Will has also placed some in our lotus pond with our fish. It is a perfect, low maintenance moist environment for mushroom cultivation.
How long will it take to fruit?
The first fruiting takes from 3 months to 2 years, although 6 months is typical. Logs can last from several years to decades, depending on the log. To encourage fruiting, logs are often soaked in water for several hours to days, then sometimes they are given a bashing!
Legend has it, a Shiitake picker in an ancient forest was disappointed one time to find there were no mushrooms in a certain spot, so in a rage he bashed all the logs with a big stick. He was amazed to find a few days later, more shiitake than he had ever seen, fruiting from the logs he bashed. Happy days, happy growing, picking and eating...fresh organic mushrooms.