Improving the yield of cold-weather shiitake by irrigation

Project Overview

Project Type: Farmer
Funds awarded in 2016: $9,374.00
Projected End Date: 08/31/2018
Grant Recipient: Philo Woodland Farm
Region: Northeast
State: Vermont
Project Leader:
Michael Walker
Philo Woodland Farm

Annual Reports


  • Miscellaneous: mushrooms


  • Crop Production: agroforestry
  • Education and Training: on-farm/ranch research
  • Production Systems: general crop production

    Proposal summary:

    This project will test methods for improving the quantity, quality and reliability of yields from cold weather shiitake strains grown outdoors on logs. Shiitake cultivation in the North East is generally based on shiitake strains that require logs to be soaked on a regular cycle to “force” fruiting. This requires time, labor, infrastructure, and often damages logs, reducing their productive life. Cold weather strains of shiitake which fruit naturally and do not require soaking present advantages to small scale producers including: less labor and infrastructure, reduced log damage, and-due to the time of year of fruiting-less slug and insect damage. Fruiting of these strains is triggered by temperature, and under optimal conditions they can produce similar or greater volumes of very high quality mushrooms per log. However when humidity is low or there are drying winds, fruiting is sporadic, requiring multiple small harvests from each log, increasing the risk of predator damage, stunting fruit growth and compromising fruit quality. In partnership with specialists from UVM we will examine the impact that highly targeted irrigation practices can play at critical times during the natural fruiting cycle to maximize yield, and reduce labor requirements by shortening the harvesting window. The results of this study will be made available to shiitake growers across the North East via web pages, workshops for growers, and presentations to state-wide and regional conferences.

    Project objectives from proposal:

    We would like to find out how water availability in the very early stages of fruiting affects the production of cold weather strains of shiitake. Specifically, by providing targeted irrigation, using different flow rates and timing to existing logs and to an experimental group of logs of different tree species inoculated with different strains we will find out whether the timing of fruiting can be manipulated so that harvest can be carried out more effectively, so lowering the risk of stunted growth, predation, and frost damage. We will measure and compare production (both quantity and quality) from logs irrigated under different regimes with existing production logs, and then the newly inoculated logs to see if different tree species and shiitake strains respond differently to irrigation.


    In Spring 2016 we will prepare groups of logs reflecting a range of log substrate species and inoculate with different shiitake strains. 270 logs will be inoculated, consisting of three groups (beech, oak and maple) of 90 logs. Each group will be further divided into three and inoculated with 3 different CW strains. Therefore 30 logs of each strain on each log species. In Summer 2016 a new laying yard will be designed & constructed with an overhead sprinkler and drip irrigation system. The design and build will be advised and supervised by staff at UVM’s Center for Sustainable Agriculture at no cost to this project. Flow meters will be installed to accurately measure the volume and rate of irrigation provided and to ensure irrigation is within the capacity of our well system. We will also explore options to filter and recycle the irrigation water where possible. It is anticipated that the irrigation system will be largely gravity fed, supplemented by a solar pump if necessary. The aim is to develop a system that can be replicated in a variety of locations, including remote areas, in keeping with the low-tech nature of cold weather shiitake cultivation. The first irrigation trials will be in Fall 2016, using 200 logs that were inoculated in 2014 and which we know produced an average of .75lb of mushrooms per flush in 2015. When temperature triggers initial fruiting, we will use different intensities of irrigation to try to stimulate a full fruiting on each log. The weight of fruit on each type of log will be recorded and fruit quality noted, and compared to the non-irrigated control. This will provide some initial results to compare with non-irrigated logs. In Spring and Fall 2017 we will irrigate half of the spring 2016 inoculated logs, ie different species and shiitake strains to fine tune our findings and see if certain combinations of wood species and shiitake strain respond more favorably to irrigation.


    2016 Late March: inoculation of 270 logs with CW strains: 90 each of beech, oak, maple 30 of each species with 3 different CW strains (Mike Walker)

    May-July: design irrigation system (Mike Walker and Project Adviser)

    August-September: set out new laying area and build irrigation system and move inoculated logs + logs previously inoculated in Spring 2015 to new laying area (Mike Walker)

    Oct-Nov 2016: 1st irrigation trial with logs inoculated in 2015 (Mike Walker & Project Adviser)

    2017 Spring fruiting: 2nd irrigation trial, with 2015 logs and 2016 groups (Mike Walker & Project Adviser) Fall fruiting: 3rd irrigation trial as above, hold workshop for mushroom growers during fruiting period (Mike Walker Project Adviser)

    October: write final report (Mike Walker) Publish and outreach on web (Mike Walker & Project Adviser)

    Outreach plan

    November presentation at NEWSG conference (Mike Walker) 2018 January presentation at NOFA VT winter conference (Mike Walker) August presentation at NOFA summer conference (Mike Walker) We envisage outreach being focused through two primary channels: Web: Promote the study and final report through our own farm website, and the website of UVM Center for Sustainable Agriculture. We will also encourage spawn producers to disseminate findings of the project on their websites. We will use the North East mushroom growers listserv (currently approximately 200 members) as a means to contact growers directly. Workshops and conferences: We will organize an on-farm workshop in partnership with UVM extension and statewide and regional non-profits to demonstrate irrigation techniques and discuss project findings. We will also seek opportunities to disseminate project findings through workshops organized by other shiitake producers as part of the NE mushroom growers network. We will submit papers for presentation at regional and state-wide conferences such as: NESWG, NOFA summer conference, NOFA VT winter conference, NOFA MA & NOFA NY

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.