Mushroom Month: Shiitake Cultivation and Land-Connection

Mushroom Month: Shiitake Cultivation and Land-Connection

By Jessica Miller, Community Forester

When many sugar maple, American beech, and a single red oak tree were harvested from Working Woods last year at this time, quite a few tree-tops were left over. This presented us with an opportunity: to reclaim some logs for mushroom cultivation. After all, nothing is wasted in a truly sustainable system, and Working Woods is meant to be a living laboratory and demonstration site for landowners to explore sustainable options for woodland management.

Mushrooms on logs are a non-timber forest product that any person with access to hardwood trees such as sugar maple, beech, or oak can cultivate. We set out to demonstrate a small-scale, 35-log operation last year, beginning with harvesting 4-6” diameter, 3.5’ logs from the leftover tree-tops. With the help of volunteers, these were then drilled and inoculated with mushroom spawn (purchased from a mushroom ‘nursery’) and the holes were sealed with cooking wax. Since certain kinds of mushrooms only thrive on certain kinds of wood, we decided to include a little experiment while we were at it… shiitake mushroom spawn was introduced to all three hardwood species, with the idea that the results would be measured. The logs were labeled and laid to rest in a cool, wet area on the north side of the Working Woods building. 9 months later, they were stacked into ‘cribs’ and then we waited as the spawn ran through the sapwood, colonizing with mycelia. This September, just in time for Mushroom Month, the shiitake logs began to ‘pin’ (fruiting bodies began to poke out of the bark of logs) shortly after the logs were soaked to increase moisture content. We have been tracking the fruitfulness of each log by weighing the harvest in order to make suggestions to landowners.

A few quick facts about Shiitake Mushrooms:

  • This edible fungus is native to East Asia, where they grow on native hardwoods including the genus Quercus (our Oaks are in this genus)
  • Shiitake are popular for their meaty, umami flavor and cancer-fighting properties
  • As a non-timber forest product, specialty mushroom cultivation on logs provides not only an interesting hobby but potential viable income, with wholesale prices per pound around $8-10 for shiitake and market prices typically around $10-12 per pound
  • Immediately after the mushrooms are harvested, they can be set ‘gills up’ in the sun for two hours to absorb additional vitamin D, which they then retain if promptly dried

This small mushroom enterprise demonstration shows that in a sustainable woodland management system, a conservation ethic can be an active ethic; woodland owners or hobbyists need not assume that the best way to care for the land is to ‘leave it alone’. In the right circumstances, wherein trees can be salvaged or appropriately harvested, people can interact directly with the land, benefiting from it, while promoting its health. Many of the hardwood trees harvested and subsequently gleaned for the mushroom logs at Working Woods were in poor health and declining value, and were removed to free up resources for younger, healthier trees while also provide an example of landowner benefit through timber income. Mushroom logs are just one more layer to this model, wherein interaction with, responsible use of, and care for woodland ‘resources’ come hand in hand with good stewardship. As Wendell Berry says, “There is in fact no distinction between the fate of the land and the fate of the people.”  Sustainability—wherein nothing is wasted, and growth is aided by death and decay—is only effective if people can learn to cultivate affection for and connection to specific places, for land. What better teachers for this principle than the equanimous, abiding and ubiquitous fungus, who turn death into yet another form of life. Cultivating mushrooms such as shiitakes from so-called hardwood tree ‘waste’ is one way to cultivate an active relationship with the land and continue the cycle of care and sustainability.

    Here are a couple lessons we have learned thus far:

    • If you decide to make a mushroom log ‘yard’, make sure your logs are in a shady, cool place where there is access to water!
    • Red Oak logs seem to produce shiitakes most prolifically; American beech are a close second.
    • Slugs LOVE mushrooms! Check the logs every day once they start to ‘pin’… sometimes the slugs will get to them first, but you may be able to prevent this by laying the logs on a tarp that can be pulled up and over the crib once logs start to ‘pin’
    • For the inoculation process, having multiple people in an assembly line is very, very helpful. Also, specialized drill bits are well worth purchasing; these tools are built for drilling holes to the exact size that ‘spawn plugs’ can be hammered in
    • Although this is a very low-maintenance enterprise, some effort is required: the biggest thing is to ensure logs don’t dry out. It is very easy for logs to dry out when there are periods of low rain; in these times, it’ll be necessary to perform ‘maintenance soaks’ of logs to ensure there’s enough moisture in the wood for the spawn to stay alive
    • A Mushroom Log “Log” of data is useful to track which logs are producing well and which aren’t; the logs we have should fruit for a couple years, each fall (the general rule of thumb is 1 year for every 1 inch of diameter, give or take depending on the ration of sapwood to heartwood)