Outdoor Hardwood Log Cultivation Précis

Cut fresh hardwood limb wood, after leaf fall and before leaf bud, from any of the following species: oak is best; sugar maple and other hard maples; alder; hickory; beech; ironwood; poplar/aspen (for oysters not shiitake); cottonwood (may be too soft for shiitake); sweetgum; birch; willow and many other non-aromatic, broad-leaf hardwoods; note that fruitwoods are notoriously poor. Note also that Poplar/aspen is best suited for Oyster mushroom production.  We have found that Shiitake does not do well on Poplar and Ash is not recommended. The density/hardness of the log determines its life span.  Softer, more rapidly decomposing hardwoods have much shorter lifespans – even ½ the lifespan.  The limb wood should be cut about two months prior to planned inoculation date so that anti-fungal substances have a chance to break down and not fight off the fungal mycelium that comprises spawn. The felled limb wood can be left in the bush/forest/woodlot and cut up into smaller sections – 3 to 4 foot-long pieces –  immediately prior to inoculation.  This will help prevent drying out the wood.  Best to keep all felled & cut logs off the ground, out of mud – stack on skids or on other logs.

Order “spawn” (fungal mycelium grown out on hardwood sawdust) during winter months.  We prepare spawn in March for delivery in late April and May.

Q: How much spawn do I need to order for my logs?
A:  Drill & Fill – a large/2.5 kilo bag is enough for approximately 20 to 25 logs (depending on diameter) that are 4 feet long. A small/1.75 kilo bag is enough for approximately 10 to 15 logs (depending on diameter) that are 4 feet long. Larger diameter logs require more holes and thus, more spawn (a larger diameter drill bit can also be used).

Totems – a small bag 1.75 kilos is enough for 2 to 3 large diameter logs;  pack more or less spawn between layers in order to use up all the spawn on fewer logs or pack less spawn between layers for more logs – perhaps up to 5 logs. Higher rates of spawn use will speed the spawn run/incubation period.

Inoculate in early spring until the end of May. A log is inoculated once and will fruit for a number of years until it is ‘spent’ and nutrients have been exhausted. Logs can be ‘forced’ by soaking to fruit every 8 weeks during the growing season or can be managed less intensively by allowing them to fruit according to natural rainfall and temperature patterns (May to November in most parts of Canada; fruiting season may be longer in some areas such as BC/Vancouver Island).

Log management involves intermittent soaking, fruiting, harvesting, and resting. You must have access to water for soaking. Logs can be soaked in a tank, immersed for 24 hours. Alternatively logs can be sprinkled for 24 to 48 hours. Note: in order to soak logs they must be immersed in water so logs must be weighted or they will float (stand log/s on end in a garbage can and place a stone on the end of the log; or put logs in a cage and place the cage in a tank prior to filling with water; the latter requires the use of a tractor and metal frames and is suitable for larger commercial operations).  Soaking logs in batches in sequence allows the grower more control over fruiting to avoid having all the logs fruit at the same time.

Following inoculation you wait approximately 1 year (depending on environmental conditions) for the mycelium to colonize the sapwood. You will begin harvesting mushrooms the following year/spring. In some climates such as BC/Vancouver Island you may get fruiting earlier – in the fall after spring inoculation. The fruiting cycle depends on rainfall and temperature patterns as well as the robustness of the spawn run.  Check the ends of logs for tell tale white mycellial ‘show’ on the ring of the sapwood.

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If you are planning to sell mushrooms you should carry out local market research and networking in order to line up prospective customers to take delivery when you begin producing – don’t wait until you have fresh mushrooms.  You should be prepared with refrigeration, packaging, such as brown paper bags or cardboard boxes, a scale, and delivery slips.