Forest-Cultivated Mushroom Production for Pacific Northwest Diversified Farms and Startups

E1) At least 17 PNW growers initiated shiitake production systems on their farms since this project began; 16 of these growers are or have been directly involved in the project as of April 2025: 

2023:

• 12 growers initiated a shiitake production system, 11 involved directly in the project
• 5 farms opted to attend a full-day training in Vancouver, WA in January 2023
• 1 farm attended a partial day training in June 2023
• 2 farms delayed implementation

2024:

• 2 growers initiated a shiitake production system, both directly involved in the project
• 1 grower from 2023 opted out of the project, 1 farm opted to delay initiation again
• 3 growers from 2023 ultimately did not follow through on communication with the Extension mentor team (TBD)
• 3 growers attended full-day trainings in Vancouver, WA (4 individuals)

2025:

• 3 growers initiated a shiitake production system, all directly involved in the project
• 4 farms attended full day trainings in Vancouver in March 2025 (6 individuals)
• 1 farm from 2023 is choosing to restart in a different location in 2026
• 6 other farms expressed that they were taking steps towards initiating a shiitake production systems in 2025, but have not followed through on communication reporting whether they followed through on initiation. 

At least 13 other PNW farms to-date have reached out to the mentor team with serious interest in starting a shiitake production system, but have not yet reported whether they also followed through on initiation.

To date, the project mentors together have made at least 30 individual visits to participating and prospective farms for consulting and mentorship on shiitake FCM systems, and periodically check-in with participating growers via email, text, or phone in the meantime.

Figure. Twelve of 17 collaborating farms have received hands-on training in Vancouver (left) to help prepare them for establishing their shiitake production systems. A total of 564 other individuals interested in producing shiitake for market have attended our workshops or other shiitake program offerings as part of this project.

Producer interviews were conducted throughout winter-spring of 2024 and 2025. In general growers chose to begin with 25-100 logs as a starting size for their production system, with most opting for a target of around 50 logs. Growers largely chose to keep their systems limited to shiitake and strains that had be previously tested by WSU Extension. One farm chose to experiment with oyster mushrooms, and another is trying a cold weather shiitake strain in a high tunnel. Most chose advisable substrate (tree/wood) species per WSU research, with most choosing red alder. At least one farm chose to add common hazel (advisable), garry oak (advisable), and wild sweet cherry (moderately advisable) and another choosing to add some bigleaf maple (largely unadvisable) and Oregon ash (unadvisable). They also largely chose to adhere to the production practices developed by Extension. A few growers chose to improvise alternatives from some of the advised standard production equipment, mostly to avert financial burdens. To date, the most common aversion to the WSU-advised production components as reported by growers has been the purchase of tanks used to soak the logs, as this is the largest single financial investment into a forest-cultivated shiitake production system. Another notable report from some growers was difficulty with timber quality control when others sourced logs for them. These growers reported delivery of logs that were either oversized, had bark damage, were the wrong species, or were dead. This was similar to some past experiences that some of the Extension team experienced as well. A tendency to over-size logs was reported by other growers that had cut their own timber as well. There was also some “reality check” moments reported by some growers regarding whether they would be able to meet their start-up production size goals with respect to labor burden, learning curve, balanced with real-time life circumstances, including physical health and fitness. Several growers accordingly lowered their target size from their initial goals.

Most growers so far considered their first year as successful; two growers considered their first year as compromised in some way. One of these growers felt overcommitted to winter projects which compromised their time and energy, while the other experienced several challenges including having to move their production site due to a land rental agreement change, trouble sourcing timber, being short of capital for equipment, and had animal damage to their shiitake bolts. Growers that generally felt successful in year one largely were farms that didn't have significant overwinter farm projects or extended-season production that conflicted with the labor demand timing for setting up a forest-cultivated shiitake production system. Several of these growers stressed that getting the shiitake work done earlier was favorable to keeping it from conflicting with other farm work in spring. Many growers also recruited family members or community volunteers to help out with the inoculation process (or wished they did), which inadvertently became an educational experience for those helping out; a few growers mentioned wanting hold workshops in the future as part of their business model. There was general anxiety expressed by many of the growers about the spawn run year and the delayed reward of having to wait for the first year of shiitake production. Growers also largely expressed that their shiitake production system was not only focused on the sheer profit margin of the mushrooms, but also that there was other value including increasing the diversity of crops they could offer to their markets (perceived extra market draw for a unique product), and being able to utilize their woodlands to increase overall farm income and business satisfaction. 

For year two, growers that followed through with Extension-advised protocols well in both year one and two considered year two to be successful with their first season of shiitake production and sales. The few farms that reported not following through on some protocols and/or had circumstantial disruptions to their process considered their second year to be unsuccessful. One of these farms from ultimately opted to indefinitely discontinue shiitake production, while two other farms decided to “reboot” for 2026 with a fresh set of logs and new production location. One farm that considered year two to be successful reported needing to pause their production in 2026 though due to a unrelated back injury. 

Most growers were risk-averse in regard to adding more shiitake bolts until they saw results from their first set of bolts; several of these growers later reported in year two that they wished they’d added more bolts to the system in year 2 in retrospect. These farms all added new bolts to their systems in 2025. Growers that were shiitake startups (i.e. didn’t already have a diversified farm business) reported gaining perspective on the economy-of-scale needed if they were to continue as a business focused mainly (or completely) on shiitake. One of these shiitake-only growers found direct-marketing their shiitake to be burdensome for them, but they were also unsure of the viability of being a wholesale shiitake grower without something like a cooperative. Conversely, growers that were adding shiitake to their pre-existing diversified farm largely reported that it integrated smoothly into their whole farm system, including marketing and overall business satisfaction, and reported that market demand appeared to be plentiful. Most of these farms reported trying value added processing with dried shiitake, and kept any extra mushrooms for personal consumption. Farms widely reported enjoying the nature of the work in year two also with regard to the system overall, being able to produce income from forests, ease of integration in their whole farm system, and working in the forest. Some who had family involved reported that their family members enjoyed it as well, with some reporting that their children took an active interest in growing shiitake as a result.

E2) The concept of a PNW forest-cultivated mushroom grower’s network was introduced to the participating producers via the January training in Vancouver and otherwise through email communication. This includes development of a network website (www.pnwforestmushroomgrowers.net; also part of E6), and a shared google drive folder for sharing resources as they are developed. A Network YouTube channel was also developed in 2024 (https://www.youtube.com/channel/UCp9itTwNDltlNvcFghlmTKQ/) for hosting how-to videos and facilitating additional Network outreach. A contact list was also shared with each of the growers to encourage peer-to-peer community support.

Network activity has been variable, with some growers actively taking the opportunity, and others not. There was a degree of resource-sharing amongst some producers to reduce financial burden and support one another. This was mostly via bulk-purchasing of supplies, equipment sharing, and information sharing. A few growers suggested that a Network “equipment library” of sorts would be a useful way for them to try out a given piece of equipment for a given season, and decide if they want to invest further. Growers generally found it difficult to coordinate and remain connected with other growers, though some still maintained that there may still be benefits. The Network website has facilitated several inquiries into shiitake production connection with local shiitake mentors, and has also allowed for emails to be collected from individuals wishing to be kept informed of shiitake educational events and other Network activity.

 E3) All Extension team members and Key Collaborator Kawai attended a full-day orientation and training in Vancouver on January 2022. The day included orientation to the past and current WSU Extension FCM research, and to Extension’s PNW-oriented production practices developed to date. PI O’Dea also participated in site visits with growers in Co-PI Jones and Co-PI Shults respective regions in spring of 2023. This co-mentoring process was used to calibrate a common Extension approach to mentoring growers utilizing the set of draft production guidance materials on forest-cultivated shiitake production systems. This also provided the Extension team with an opportunity to review the production materials in a real-time context. The materials were also used to outline a set of uniform practices for Co-PIs Jones and Shults to use in establishment of their respective regional trials, giving them a first-hand user opportunity to review the draft guidance materials.

In 2023 PI-Shults also presented on the project at the River Restoration Northwest Conference in Skamania, WA (~350 attendees) to a mixed array of stakeholders including a significant number of forestry researchers, educators, and other technical service providers. In 2023 Co-PI Shults also facilitated new connections regarding strain development (via connections made in Japan, see E4) with Field and Forest Products, the largest North American producer and retailer of spawn and equipment for forest-cultivated shiitake production. In 2025 this led to an opportunity to trial a new shiitake strain that originated in Japan. Similarly, in 2023 Co-PI Jones facilitated new connections and potential collaborations with the only other US producer retailing multiple strains of spawn for forest-cultivated shiitake production, Northwest Mycological Consultants. In 2025 Co-PI Jones also built connections with two other Oregon-based Extension agents and with Hopkins Demonstration Forest (HDF) in Oregon City, OR. This resulted in Co-PI Jones conducting a training on shiitake production with 10 Extension and HDF staff participants in 2025, in order to help facilitate further dissemination of shiitake production information and potentiate HDF as a future research and demonstration site for Oregon.

E4) A 10-day visiting scholar tour of select shiitake production, processing, and research sites in Japan was organized through critical efforts made by key collaborator Kawai throughout the first half of 2023. The tour occurred between July 27^th- August 6^th, 2023 and occurred in several locations in Oita, Miyazaki, Kumamoto (on the southerly island of Kyushu), and Hokkaido (on the northerly island of Hokkaido) prefectures in Japan. In addition to Key Collaborator Kawai, PI O'Dea and Co-PIs Shults and Jones participated in the tour. Co-PI Zobrist was unable to attend the tour due to unanticipated time constraints. The team documented the tour through video and photography for future dissemination throughout the remainder of the project and thereafter. The tour consisted of meetings with researchers at three different government-run research stations (Oita, Miyazaki, and Hokkaido), meetings with three different industry groups (Kumamoto, Miyazaki, Tokyo), and seven farm visits with shiitake growers (2 in Oita, 3 in Miyazaki, 1 in Kumamoto, and 1 in Hokkaido). The tour of Japan provided the researcher/mentor team with novel insights (some mentioned in R5) on shiitake production and forest-cultivated mushrooms in general. It also importantly provided affirm that our research and methods developed for the PNW were generally on-point and appropriately innovative.

Although Japan is the pre-eminent country producing shiitake on logs at commodity-scale levels, the vast majority of shiitake mushrooms (and other mushroom species) are nonetheless produced in indoor climate-controlled facilities on sawdust substrates. Partly due to this shift in production method and a declining population of individuals going into farming, log-grown shiitake is generally declining. The remaining log-grown shiitake industry is dominated by long-term/lifelong growers, and/or growers that simply prefer the process of producing shiitake this way. There are initiatives from both industry and Japanese government (often local) to bolster log-grown shiitake production culturally, and by touting the distinct qualities and heritage of log-grown shiitake vs. those grown indoors on sawdust. Drying and processing equipment and facilities are also often bolstered by government programs or may be cooperatively owned. Wood used for log-grown shiitake is almost exclusively on two species of oak (Quercus acutissima and serrata), and it is not uncommon for trees to be planted with shiitake production as the intended end-use, and for timber to be provided by a third party service rather than by the shiitake grower.

Japan has also developed "hybrid" systems for producing shiitake on logs, which makes use of open or indoor shaded hoophouse type structures instead of outdoor spaces under forest canopy. The majority of shiitake produced outdoors on logs under forest canopy (i.e. forest-cultivated) is being grown for dried shiitake markets. Forest-cultivated shiitake for dried shiitake markets is somewhat of a lower-input system that generally makes use of lower inoculation rates and plug spawn (which facilitates a slower spawn run rate), and colder weather strains (which fruit more spontaneously, in accordance with seasonal shifts in temperature). Fruiting in these systems may be sometimes assisted by overhead irrigation and/or physically striking the bolts instead of soaking bolts (forced-fruiting). Colder weather strains are used in outdoor shiitake production because the natural shiitake growing season is more oriented towards late fall and early spring, which tends to be the drier part of the year in Japan. This production season timing is notably different than the PNW, where the shiitake production season needs to be oriented towards late spring/early summer through late summer/early fall due to the PNW having the opposite precipitation pattern.

Alternatively, log-grown shiitake for fresh markets in Japan though tends to have more in common with PNW shiitake production. Japanese fresh market shiitake growers tend to use of sawdust spawn, wide range and warm weather strains, and higher inoculation rates- practices that are similar to the PNW. Sometimes midsummer weather in Japan is more prohibitively hot (partially due to nights remaining warm) for producing shiitake though compared to the PNW. Fresh market log-grown shiitake production in Japan also often uses shaded hoophouse structures for 1) quality control and 2) season extension; use of these structures is often bolstered by government purchase assistance programs. This approach is somewhat similar to the PNW; while shaded hoophouses are not a standard practice in PNW log-grown shiitake production, the "fruiting tent" approach that we've developed for outdoor production in the PNW (where sets of ~25 bolts are completely wrapped in breathable fabric during fruiting) serves a similar purpose regarding quality control, but is a far lower-input/financial investment than a hoophouse-type setup. Innovative fresh-market shiitake growers in Japan also may make use of hoophouses as an environmental control accelerating spawn run; these growers and may often also rely more heavily on direct marketing in urban centers to overcome low prices that they would otherwise receive from wholesale commodity markets. The latter context is also similar to what would be encountered in the PNW by new and beginning forest-cultivated shiitake growers.

Our tour also exposed the team different production approaches and specialized equipment that is currently not accessible to US growers. In addition, it also allowed us to develop an important connection with one of the major innovative spawn companies in Japan, Fujishukin (Fuji Spawn). PI-Shults and Key Collaborator Kawai were able to meet with a company representative just before returning to the US, during which they learned that Fujishukin also had pre-established connections with Field and Forest Products in the US. In January of 2024, PI-Shults convened a meeting between the research team, Fujishukin, and Field and Forest Products in order to discuss shiitake resources that may be useful to PNW growers and possibilities for accessing strains with potential to perform well for PNW growers. In 2025 this connection let to an opportunity to trial a Fuji strain via Field and Forest Products.Figure. Images taken throughout the visiting scholar tour of Japan. Japan is the only country where shiitake is still produced on logs on a large scale, either traditionally under forest canopy (A), under open shaded structures (B) or inside shaded structures such as hoophouses/high tunnels (C,E). The project research team gathered information on specialized production equipment that is not available in the US (D), and novel, innovative production approaches used by Japanese growers (E), such as the pictured grower's space-efficient indoor fruiting racks and burning of spent shiitake bolts as a heating source to help produce shiitake into the winter months. The team also built connections and exchanged information with Japanese researchers in public institutions (F,G) and private industry (H) in order to better inform shiitake production developments in the PNW.

E5) Adaptations to the original E5 objectives were driven by logistical and circumstantial constraints related to where and when it was most feasible to hold educational events, or when alternative opportunities arose. Hands-on workshops in particular needed to be well-timed and occur at a venue that that had adequate shelter, electric service, parking, and could accommodate logs, the noise of holes being drilled, and wood chips and wax drippings getting on the floor. The venue also otherwise needed to have space for giving a presentation or have an educational backdrop that could help facilitate learning about other aspects of shiitake production. Because the Vancouver site (The 78^th St Heritage Farm) had all of these aspects, it was used as the primary venue for working towards educational objectives. Spaces available to each regional Co-PI were more restricted with the exception of Co-PI Shults’ location (Meyer’s Point Environmental Field Station). Hands-on workshops held in spring were found to be the most feasible timing because it is when farmers were less busy, and allowed participants to try inoculating logs with shiitake. Summer workshops focused on shiitake harvest were phased out due to difficulty in synchronizing dates where shiitake mushrooms were optimal for viewing and demonstrating harvest, plus general poor grower turnout at that timing.

Eight hands-on trainings for participating growers have been held to date in Vancouver (2x in 2023, 4x in 2024, 2x in 2025). A total of 125 participants have taken advantage of six hands-on public workshop offerings in Vancouver (1x in 2022, 1x in 2023, 2x in 2024, and 1x in 2025) or at nearby Headwaters Farm Incubator (1x 2024, in Gresham, OR) to date. Another 42 participants attended a field day in Vancouver in 2023 that included a shiitake demonstration. In the South Puget Sound region, 97 participants have taken advantage of four public hands-on workshops (1x in 2023, 1x in 2024, and 2x in 2025) to date. Ten other participants took advantage of a hands-on public workshop in northwest WA in 2024, and 30 participants attended a field day demonstration in 2024 as well in northwestern WA. Currently, three more hands-on public workshops are scheduled for late April 2025 (2x more in Vancouver, 1x more in northwest WA).

In 2023, A conference session on shiitake production was given at the OSU Small Farms School to 29 attendees. In 2025, a webinar was given to 147 participants, and a presentation/demonstration was also given to 40 participants in at the 2025 Western WA Forest Owners Winter School.

The vast majority of participants that attended our public shiitake events were interested in learning how to grow shiitake for market, although many indicated that they wanted to try growing shiitake for personal use first. Post-event evaluations thus far have indicated significant knowledge gains, and intent to put knowledge gains to use. This includes intent to pursue shiitake enterprise development, but also includes indications that workshops have informed some attendees decisions not to start an enterprise- an important, but under-appreciated outcome that saves would-be new growers the considerable expense of a potential business failure or dissatisfaction.

For general project outreach and indirect education, a CO-PI Jones hosted a shiitake mushroom tabling event at the Maple Conference in Portland, OR in 2023 reaching approximately 350 people, and at a forestry field day in 2024 to another 75 individuals. To date, the www.pnwforestmushroomgrowers.net website has accumulated 1649 visits (1242 unique, and 407 repeat visitors) with 2299 total page views. Two shiitake podcast episodes were also produced in 2024, with at least 478 listens to date. Two how-to videos were produced in late 2024 as well that have received 78 views to date. The project also received press coverage in 2023 through articles by WSU Insider and the Capital Press about the project and the visiting scholar tour of Japan:

• https://www.capitalpress.com/ag_sectors/smallfarm/western-innovator-research-cultivates-shiitake-mushrooms/article_535a0890-9534-11ee-a07c-4394b29c1e12.html
• https://news.cahnrs.wsu.edu/article/new-wsu-extension-program-growing-network-of-northwest-shiitake-producers/

The team has also been invited to contribute an article about the project to Northwest Woodlands magazine’s fall 2025 issue.

E6) Multiple educational materials on forest-cultivated shiitake production have been drafted since 2023. These include 1) a 20-page illustrated production guide, 2) a shiitake production enterprise budget worksheet/calculator, 3) a table of PNW-sourced log substrates for shiitake production, 4) a visual two-year production timeline, 5) a quick-reference “to-do” production startup checklist, 6) an inoculation rate table and row-spacing pattern guide, and 7) three draft how-to videos. Most of these materials are not in a final, publicly-accessible form yet, but have been provided to all collaborating growers and participants from each shiitake program. The information contained in them is also incrementally being reformatted and made public through the Network website (discussed below). Two other how-to videos were produced in 2025 and made public in a finalized form on a new Network YouTube channel established for hosting videos and facilitating further outreach. A guide intended for non-commercial shiitake growers (home gardeners, hobbyists etc.) was published in February of 2025, after recognizing a need for a discrete forest-cultivated shiitake growing guide specifically tailored to this sector of the community. Co-PI Jones also developed a shiitake production poster in 2025 to be used in Oregon forestry outreach events.

The PNW Forest-Cultivated Mushroom Growers Network website (www.pnwforestmushroomgrowers.net) was initiated in 2022, with nine pages published throughout 2023. In 2024 six other pages completed in to get the site to a comprehensive state and incorporated 1) additional video and visual media and 2) links to select printable guidance materials. Ongoing improvements and additions will continue to be made, and the website will ultimately contain all the information provided through the draft guidance materials along with shiitake research summaries, and other resources for growers.

All participating growers are being solicited for feedback on the materials during year-end interviews throughout the project. To date, participating growers largely found that the production guidance materials provided by Extension to be helpful and thorough, although a few growers suggested improving clarity on the timeline of production activities and on strain selection, and to add more information to help with navigating marketing. A majority of growers remarked that instructional videos were the most effective educational product as they offered the closest alternative to a hands-on, individualized educational experience. Several growers remarked that they felt the shiitake production system developed by Extension provided a low-risk, clear path to successful production if growers were willing to refrain from deviating from guidance at least throughout the establishment process and first harvest year.