Green Horizons

Interest in fresh shiitake mushrooms is increasing with gourmet chefs, farmers' markets and household consumers, as information spreads about their nutritional benefits and rich, versatile taste. Markets for shiitake and other specialty gourmet mushrooms continue to show promising profit potential for Missouri forest landowners.

Cultivating shiitake mushrooms allows forest landowners and home gardeners an opportunity to utilize trees thinned from woodlots as well as branch-wood cut from the tops of larger trees. When the mushrooms are harvested and marketed, the result is a relatively short-term payback for long-term management of wooded areas.

The practice of intentionally managing shade levels in a forest to favor the production of certain crops represents the agroforestry practice called forest farming. Properly applied, forest farming can enhance and diversify income opportunities, while at the same time improving the composition and structure of the forest for long-term stand health and economic value. By developing an understanding of the interactions between the overstory trees and the understory environment, forest management activities can be used to create understory sites ideal for growing profitable shadeloving crops like shiitake mushrooms.

University of Missouri Center for Agroforestry experts have been working since 1999 to determine the best logs, strains and spawn for growing shiitake in Missouri.

UMCA mushroom studies were quite "fruitful" in 2007 as numerous research questions were answered to help growers, including:

• Sugar maple logs outperform oak as mushroom hosts (especially when sugar maple are harvested in February).
• Wide-temperature shiitake strain outperforms warm- and cold-weather strains.
• Sawdust spawn outperforms dowel or thimble.
• Fruiting is most abundant in years two and three after logs are inoculated. Although fruiting will continue for about six years, gradually declining, contaminant wood-decay fungi will become increasingly prevalent.
• Chilled immersion water improves mushroom yield; well water is recommended over surface water when force fruiting (soaking logs in water to simulate natural rainfall and encourage mushrooms to fruit).
• Force fruiting compresses and increases production of logs to three years (spawn run plus two).
• The efficacy of force fruiting depends on ambient temperatures and the spawn strain used. Cold-weather strains respond poorly to force fruiting.

A completely updated version of UMCA's Agroforestry in Action: Growing Shiitake Mushrooms in an Agroforestry Practice, is now available online at http://www.centerforagroforestry.org/pubs/index.asp#mushguide

This guide, authored by MU's Johann Bruhn, research associate professor, Division of Plant Sciences, takes landowners step by step through the growing process, from managing shade levels for production to marketing the fresh mushrooms. New findings are incorporated throughout the publication.

The printed version of the revised guide is coming soon - contact Michelle Hall, senior information specialist with UMCA, at hallmich@missouri.edu or 573-882-9866, to be placed on the list for a copy. In the meantime, view and/or print off a copy at the site above.