Updated: Sep 12
Outdoor mushroom patches are a brilliant way to increase soil health, and get healthy organic mushrooms in the garden! There are two types of edible and useful mushrooms that can be easily grown in your garden. Both grey oyster mushrooms and king stropharia mushrooms are wood decomposers and can quickly break down biomass such as fresh wood-chips into healthy, rich soil. We may as well start with the king ...
(Stropharia rugosoannulata) a.k.a. Wine Cap a.k.a. Burgundy Mushrooms a.k.a. Garden Giant
King Stropharia has many names and many uses. It is extraordinary in that it is a primary and secondary decomposer, and has many beneficial properties, including the ability to trap and eat some root-eating nematodes, boost the growth of certain plants such as corn, benefit local bee health & immunity, attract earthworms, and even filter water in an aquaponic or permaculture setting. King stropharia is an edible mushroom that is easily identified in the garden by its burgundy-wine coloured cap in its younger stage. This species tolerates full sun and can last for years by adding fresh biomass every year for nutrients.
How to set up a King Stropharia patch
Ideally, you would like hardwood sawdust/ wood-chip** -- less than 25% fresh pine/ conifer wood-chip, that is no older than 6 months -- be sure your wood-chip is wood-chip and not bark. Scrape the intended patch area down to soil or low-cut grass, then add a 2-4 inch layer of fresh wood chip followed by a layer of your king stropharia spawn, followed by another thicker layer of wood chip about 6-12 inches (for larger patches with lots of spawn repeat previous steps, layering spawn with wood chip until all spawn is used). Bed should be no thicker than 24 inches thick. Hand spread at a minimum of 1kg of spawn per square meter. We strongly recommend using 2kg of spawn per square meter, this higher spawn rate is much more likely to establish, survive the winter, and produce mushrooms the first year!
Once you install the king stropharia patch, keep it undisturbed for about 4-6 months. Planting crops normally through the area is fine. Inter-planting corn, zucchini, squash and pumpkin in the mushroom patch is especially good for both the crop and the mushrooms. We have noticed pumpkin crops make a humid micro climate under their leaf canopy leading to abundant fruiting! After about four to six weeks you can check to see how the mycelium is growing by digging a small hole into the wood chip. You should see thick white mycelium starting to grow off of the spawn onto the fresh wood chip, like the photo above. Keep it well-watered through summer, same as watering your veggie garden is sufficient. You can check the moisture content of the wood chip easily by scraping back 1 inch of chip and you can visually see if it is damp by the darker colour of the wood chip. Before winter, you will want to add a thick layer of wood chip, about 3-5 inches, to protect from frost: over winter the mycelium will retract down to protect from frost, and grow back again in spring. Adding any synthetic fertilisers to wood chip is not advised.