Growing gourmet mushrooms on logs
With the arrival of autumn, now is the perfect time to prepare and inoculate your logs with delicious shiitake mushrooms, so you can look forward to harvesting mushrooms to eat with your fresh garden herbs. Growing gourmet mushrooms on logs is easy, low maintenance and super rewarding! Shiitake is the most commonly grown on logs, however you can also grow other varieties such as Nameko and Blue Oyster...now is the time to give it a go!
You don't need large sheds and lots of technical expertise and equipment to grow gourmet mushrooms on logs using inoculated dowels. Growing gourmet mushrooms on logs with inoculated dowels, anyone can grow mushrooms, even in a small apartment with little space.
At the home of Forest Fungi, Will Borowski has use the above method to inoculate large logs, terrace the garden and incorporated mushrooms into the garden bed (we call it myco-permaculture). You can use the method to be as small or large scale as you like!
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 (e.g Nameko).
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 Stamet's 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.
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 need 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.Will calls it ‘mycoaquaponics’. It is a perfect, low maintenance moist environment for mushroom cultivation.
How long until it will 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 delicious organic mushrooms.