Workshop teaches ins, outs of shiitake mushroom

ANDY HALLMAN/Ledger photo

Jesse Knox leads a workshop on shiitake mushrooms Tuesday in the Activities Building at the Jefferson County Fairgrounds.
ANDY HALLMAN/Ledger photo Jesse Knox leads a workshop on shiitake mushrooms Tuesday in the Activities Building at the Jefferson County Fairgrounds.

Fungi enthusiast Jesse Knox hosted a workshop Tuesday on how to grow shiitake mushrooms in your own backyard.

Twenty-seven people attended the program in the Activities Building at the Jefferson County Fairgrounds. Taylor Trudell, horticulturalist at ISU Extension and Outreach Jefferson County, organized the class. Knox spent the first half of the meeting reviewing facts about the mushrooms such as what trees they grow on and the best environments for them to fruit. He said they are an exceptionally healthy snack, high in Vitamin D, protein, fiber, zinc, and contain compounds that fight cancer and boost immunity.

The second half of the meeting was a hands-on exercise where the participants were given wood pellets loaded with shiitake spores. Each person was given a log that Knox had drilled holes into before the meeting. The participants hammered the pellets into the holes to “plant” the mushrooms, then sealed the holes with wax. They were instructed to take the log home and place it in a shaded spot away from the wind so it doesn’t dry out. Logs should be watered heavily once a week if there is no natural precipitation.

“These logs could fruit anytime between September and December, if the weather cooperates,” Knox said. “Each log could produce 1-2 pounds of mushrooms per harvest.”

Virtue of patience

Many of Tuesday’s attendees had never planted shiitake mushrooms before, but were eager to try. Knox said the main thing beginners must remember is patience. The variety of shiitakes the participants got fruit in six to nine months, but a cold-weather variety can take nine to 18 months, or even longer. Knox said he once had to wait two years for his shiitakes to fruit.

If you can master the virtue of patience, you can grow shiitakes, because they are a fairly low-maintenance source of food. No weeding is required, but it wouldn’t hurt to protect them from pests. Chipmunks and squirrels like the taste of mushrooms, so Knox recommends building a cage of quarter-inch mesh wire to put over a stack of shiitake-infused logs.

Another common pest is the slug. Knox said one way to fight them is to get ducks, which love to eat slugs.

Iowa is a great place to grow shiitakes. The fungus does best in oak trees, and quite well in maple, two varieties that abound in Iowa.


According to Dr. Leonard Perry of the University of Vermont, shiitake mushrooms (pronounced like “she talkie”) have been grown for thousands of years in Asia, originally found in mountainous regions. The word “shiitake” is Japanese, a compound of “shii” (the hardwood tree where it’s found) and “take” (mushroom).

Knox said the Japanese noticed that when a branch or trunk died and fell to the ground, it would be covered in snow for the winter. In the spring, the snow melted and soaked through the log. Later, mushrooms would emerge from the log. They realized they could produce these shiitake mushrooms by soaking logs in cold water, 20 degrees colder than the air, for 24 hours.

Over time, scientists learned that shiitake mushrooms grow best when the logs are allowed to rest eight weeks after harvest, before they are soaked again for another round of fruiting.


Don Frizzell drove 90 miles from Corydon to attend Tuesday’s workshop. He grew shiitake mushrooms 15 years ago, but thought he could use a refresher course.

“Growing up in Iowa, hunting for morel mushrooms was a big thing,” he said.

Frizzell said he likes to cook mushrooms in a stir fry with other vegetables. He’s looking forward to harvesting shiitakes because they’re one of the easiest mushrooms to grow.

Kelly Mae Heroux said she knows a bit about shiitake mushrooms, having planted 50 logs in her former home of upstate New York. However, she left them for someone else to harvest when she moved to Fairfield. She said she’s got a place in mind where she can keep her new log where it won’t dry out.

Casey Carlson and Lark Dunham said this will be their maiden voyage into growing mushrooms. Carlson loves to hunt morels. Even if he doesn’t find them, he enjoys spending time in the quiet wilderness.

Nick Broz said this is his first time growing shiitakes, too. He and his family hunted morels for years, and then a few years ago he became interested in other edible mushrooms.

“There are a lot of good resources in this area to learn about mushrooms,” he said.