Radical Mycology’s long time friend, Pat Rasmussen with Edible Forest Gardens in Olympia, made an incredible amateur mycological discovery the other day. Pat regularly installs perennial gardens in the Olympia area, often with the Elm Oyster mushroom (Hypsizygus ulmarius) as a potential companion for the plants. But when a local big-name mushroom farm accidentally sent her the wrong kit, she ended up installing the Nameko mushroom (Pholiota nameko) instead. 5 months later, the result were incredible. The perennial Aronia plants (similar to blueberries) planted in the area with the mushroom bed grew over twice as large as those plants grown without the mushroom companion. And the grape plants in the area did much better as well. As with all great scientific discoveries, this accident leads to a new realm of exploration in the field of plant companioning.

Why do some decomposing fungi help plants grow? The answer isn’t clear. In the book Mycelium Running, Paul Stamets worked with a research student to determine whether specific saprotrophic mushrooms would be beneficial to certain food plants if grown in proximity. After a season of growth and various plant and mushroom pairings, a few strong results surfaced. Notably, the Elm Oyster was found to dramatically increase Brassica plant growth and yield, while other pairings (such as normal Oyster mushrooms [Pleurotus spp.] paired with Brassicas) were shown to actually be detrimental to the plants. The exact reason for this is unknown. As both these mushroom species are aggressive decomposers, it can’t simply be the nutrient and carbon dioxide release. Perhaps specific enzymes being released by the Elm Oyster works to stimulate the Brassica plant’s roots or supports the soil flora. Chances are, there might be many more beneficial plant-mushrooms pairings that have yet to be discovered.

Pat’s accidental discovery is notable for 3 main reasons: ..............

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