{"id":246,"date":"2025-03-19T13:11:22","date_gmt":"2025-03-19T20:11:22","guid":{"rendered":"https:\/\/extension.wsu.edu\/wrlp\/?page_id=246"},"modified":"2026-03-31T09:38:59","modified_gmt":"2026-03-31T16:38:59","slug":"shiitake","status":"publish","type":"page","link":"https:\/\/extension.wsu.edu\/wrlp\/forestfarming\/crops\/shiitake\/","title":{"rendered":"Forest Cultivated Shiitake Mushrooms"},"content":{"rendered":"
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Background<\/h2>\n\n\n\n

Forest cultivated shiitake is an agroforestry practice that can reliably produce high-quality shiitake mushrooms in a forest using logs as substrate.  This method has been developed over 1,000 years in Japan and China, where shiitake is a native species.  In the 1980\u2019s, this method was adapted to the eastern U.S., where shiitake is not native. This practice is low risk, requires minimal space and equipment, and yields a high-value mushroom that is ideal for direct-to-market sales to restaurants, at farmer\u2019s markets, or as supplement to a CSA.  It utilizes small-diameter hardwood logs as substrate, which makes it compatible with forest enhancement practices like thinning.  Today, most shiitakes are produced using bags of sterilized sawdust in climate-controlled facilities.  However, log-grown shiitakes still provide an opportunity for farm and forest owners to diversify and supplement their income.  <\/p>\n\n\n\n

There are fewer forest cultivated shiitake producers in the Pacific Northwest, largely due to a lack of research and guidance available to support the adoption of the practice to the unique climate and hardwood species in the region.  However, WSU Extension began researching this in 2019 and is actively developing best practices for commercial-scale and hobbyist shiitake cultivation in Washington State (see below for details).<\/p>\n\n<\/div>\r\n\n\n

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Overview<\/h2>\n\n\n\n

Cultivating shiitake on logs is a relatively simple process but it does require time.  Small diameter hardwood trees (e.g. red alder) are felled in the late winter to provide fresh substrate (downed wood collected from the forest floor won\u2019t work).  Those trees are cut into four-foot lengths (called \u201cbolts\u201d) in the spring and then \u201cinoculated\u201d by drilling holes in them, filling the holes with shiitake spawn, and then covering them with wax.  The bolts are then moved to the forest where they will have sufficient shade for the spawn run, which is the period required for the shiitake to fully colonize the log.  This is typically a full year from the time of inoculation, after which the bolts can be forced to fruit by soaking them in cold water for 24 hours.  Bolts can be force fruited 2-3 times per year for multiple years, before the carbon and nutrients in the log are spent.<\/p>\n\n\n\n

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It takes time for the shiitake fungus to colonize a log before you will be able to harvest any mushrooms, but the log will produce for several years afterwards. Graphic by Eric Jones, OSU.<\/figcaption><\/figure>\n\n\n\n

A small-scale commercial system would likely start at 100-200 logs while larger operations will have several hundred to 1,000+.  Much of the labor for this process occurs during inoculation, but most commercial operations will add new logs every year to maintain yields.  Some specialized equipment and supplies are necessary, including a modified angle grinder, inoculation plungers, and shiitake spawn, but farmers will often have much of the other necessary equipment already (e.g. chainsaw, sawbuck, t-posts).  Livestock tanks are often the most expensive investment, which are used to soak the shiitake logs and force fruiting. <\/p>\n\n\n

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