Building a stack is a faster and easier method of growing mushrooms on logs and is well suited for several species including oyster mushrooms. Essentially, the method involves creating a ‘layer cake’ of short sections of a log stacked vertically on top of each other with a layer of spawn spread between each section (the filling).
One 1.5kg bag of sawdust spawn will inoculate about 5 stacks.
When and where to make your stack
- We recommend making your stack in the spring when the tree can be felled before green –up (or leafing out). The climate is relatively cool and damp in the spring and there is plenty of good weather for the mycelium to establish before winter.
- Place your stack in a shady spot that provides a relatively cool, moist microclimate for the fungi to grow. Examples include under a tree, in a forest or a shady, protected spot created by your house or garage.
Step 1: Select the log
- Logs should be cut from a healthy living tree ideally in late winter/early spring while still dormant. The tree should have no signs of other fungi. For our own experience, we find the best logs are from a healthy tree cut down in the spring before the tree leafs out but after the sap is running. We live in an area that is slightly cooler than nearby cities so when the trees in the city leaf out, we know we have about one week to cut down our trees.
- Once you cut down the tree, ensure it is not rotting from the inside. These trees will not work for mushroom cultivation. It is also best if there are no large gashes in the bark that would allow wild fungi to colonize
- Generally logs should be between 9 -14 inches in diameter. For length, you need approximately ~3′
- The type of wood you use will depend on the local species of trees available to you and the species AND strain of fungi you want to grow. For example, in general:
- Oyster mushrooms: Beech, Elm, Maple, Willow, Cottonwood Poplar (Aspen);
- Lions Mane: Oak, Sugar Maple, Beech (the best!);
Step 2: Prepare the stack
- Buck the tree into approximately 16″ lengths (x2) with a 4″ “cookie” for the top
- Bottom log – 16″
- Middle log – 16″
- Top log – 4″
Step 3: Inoculate the stack
- Makes sure that you are stacking your log vertically the same way it would have naturally grown
- You can use sawdust spawn to inoculate your log. If you use grain spawn it is more likely to be eaten by critters (see varition below for using cardboard inoculated with grain spawn).
- In a shady location protected from drying winds, place a piece of cardboard on the ground to minimize competition with wild fungi and bacteria. Add some broken up sawdust spawn, then place the first section of the log on top (ensure all the sawdust spawn is covered by the log)
- Cover the top of the log with more sawdust spawn. We add about 1/2″ of sawdust spawn
- Place the second section on top making sure to align the vertical lines on each of the two sections that you drew earlier so they fit in their original orientation.
- Repeat this process until all sections and the cookie are reassembled.
Step 4: Label and cover the stack
- Label you logs so you can learn from you experiments and know which mushroom species the log should be producing. Use a weather resistant tag and label it with the following:
- mushroom species
- wood type
- Place a large plastic or paper bag upside down over the stack making sure it covers the entire stack
- Pull the bag not quite closed, leaving an air pocket and enough space for air flow. Secure it with string so it does not blow away. (We have little wind so do you do this step)
Step 5: Establishment Phase
- Keep the stack covered until it is fully myceliated indicated by white mycelium between the sections of wood and down the sides of the stack
- Depending on your local climate and the year, it may take 3 to 6 month or even until the following spring for the stack to fully myceliate
Step 6: Maintenance, Overwintering and Harvest
- Once fully myceliated, remove the bag.
- If humidity is low (below 50%) then water with sprinkler every couple of days
- Keep the stack covered to over-winter and place it in a protected area
- Unlike ‘logs’ you don’t need to trigger the mushrooms to fruit with an influx of water, rather wait for a good spring or fall rain during cooler temperatures to trigger them for you!
- Instead of using sawdust spawn as your ‘filling’ layer, we first inoculated cardboard with grain spawn and once it was myceliated, inserted it between the sections of stack. It worked well! It also ensured a smaller gap between the layers. (The cardboard is not as thick as a 2″ layer for sawdust spawn)
Fungi Akuafo Experience
- This is our favourite technique! Why:
- Least time consuming technique
- Requires not special tools
- Require little maintenance
- Our experiments have worked!
- We have used the following species to create log stacks:
- Pearl Oyster (Pleurotus ostreatus)
- Garden Oyster (Hypsizygus ulmarius)
- Blue Oyster (Pleurotus ostreatus columbinus)
- We use Trembling Aspen (Populus tremuloides) for our log stacks as those are the hardwood trees we have available
- We do not use cardboard at the base of the stack. We use plastic. We have noticed that cardboard left outside in our forest quickly colonizes with wild fungi
- We place the logs in our mixed boreal forest (very shady – moss shady!)
- We have seen pictures of people using paper instead of plastic. Give it a go!
- When you fruit mushrooms outside, you attract insects, slugs, beetles etc. You need to harvest the mushrooms ASAP! Be prepared to share your lunch with some fried worms…
- We use oil based markers with flagging tape to mark our outdoor experiments. Regular Sharpie pens will fade very quickly. Other alternatives include cooper tags that you write by creating indents in the metal. We also create maps of where we place our logs so that we have a copy of our experiments in a digital format
- You should be able to inoculate at least 5 or 6 log stacks with one bag of our sawdust spawn
- Most books call this technique “Totems”. We didn’t feel that was an appropriate term