Growing mushrooms on logs is a simple, low maintenance way to enjoy fresh mushrooms from you backyard for a few years. Without the need for a lot of room, you can grow a diverse range of nutrient dense, organic mushrooms even in urban settings and small backyards.
There’s a variety of different types of edible mushrooms that can be grown on logs.
This includes Shiitake, Oyster varieties, Coral Tooth (aka pekepeke kiore, NZ native cousin of Lion’s Mane), Enoki, Turkey Tail (used for medicinal purposes in teas and tinctures) and Tawaka (aka poplar mushroom, NZ native similar in taste/texture to pioppino or chestnut mushrooms).
Log cultivation doesn’t have the same predictability or consistency as growing mushrooms indoors because of the ranging environmental factors, but it is much less maintenance and closer to the natural way mushrooms grow in the wild. Growing mushrooms on logs is also more long term and sustainable, as it can take up to a year to fully colonize and start producing mushrooms. Once a log is fully colonized, it can produce mushrooms twice a year
(spring and autumn) depending on weather conditions.
Types of Logs Most types of hardwood will work. This includes alder, beech, elm, aspen, birch, poplar, oak, maple, willow, hickory, fir, gum etc. For poplar and willow, you may want to put the logs in the garage or in the dark off the ground until they stop trying to sprout before inoculating with dowels. Fruit trees are less ideal and are known to produce lower yields. Avoid using cedar, black locust, walnut and most conifers.
Ideal Log Size The bigger the log, the longer it will take to colonize and the longer it will produce mushrooms. Ideal size would be 100mm-200mm by 1 meter long, you want to plug your logs within a few months of cutting. The log should be clean, free of dirt (lichens and mosses are ok) and always kept off the ground to avoid unwanted contamination. Logs can be soaked under water for a few days or up to a week before plugging with dowels. Soaking isn’t 100% necessary, but does help the mushroom colonize and take over the log faster.
Plugging Logs with Dowels You will need:
dowel spawn (dowels that have been inoculated with the desired mushroom culture)
hardwood log/logs, freshly cut and not sprouting
power drill and 9.5mm drill bit
parafin, soy or beeswax
natural brush to apply wax
small pot to melt wax
Step 1- Drill holes about 32-35mm deep in rows all over the log about 15cm-20cm apart starting 50mm from the edge of the log. Rows should be spaced about 7-10cm apart, forming a diamond pattern.
Step 2- Hammer your dowels in immediately in your drilled holes.
Step 3- Melt wax at high heat (almost to smoking point) and apply to plugged dowels and the ends of the logs. This helps with moisture retention and protects from unwanted competitors.
Step 4- Find a good place for your log in a shady area out of direct sunlight and KEEP OFF THE SOIL to avoid competition from other fungi.
Step 5- Water your logs over summer every two weeks or along with the rest of your garden. For best results, soak logs underwater for 24 hours in the middle and end of summer.
Step 6- Keep an eye out for mushrooms from four months to a year. Well colonized logs will turn white on the ends (this is mycelium or mushroom roots). Naturally, the mushrooms will come out around autumn/spring when the temperature drops/rises but the air is humid, usually after rainfall.
You can ‘force fruit’ logs and trick them into producing mushrooms once fully colonized by soaking in cold water for 12-24 hours. The log will keep producing mushrooms until it runs out of nutrients, the general rule of thumb is 1 year of production per 2.5cm (1in) of diameter.
Using the 'totem method'
An even simpler method than using dowels is 'the totem method.' For this all you need is a chainsaw, sawdust spawn of choice, and a decent sized log so that you can stack it up like a tiki. Larger diameter logs are ideal, about 300mm wide or wider. Basically, all you need to do is to cut your log into rings, about 200mm apart, restack them (in your chosen spot) with a 1-2in layer of broken up sawdust spawn in between each layer. Somewhere with some sort of support could be necessary depending on your log diameter and height. The log still requires shade to prevent drying out in the sun. For ours, we simply put burlap sacks over the logs and make sure to water them often in summer.
Harvesting Mushrooms Although it is reasonably unlikely another species will grow on the log, it is definitely possible that other wood rotting variety of mushrooms could grow in its place. It is important to be able to properly identify the intended mushroom before harvesting. Our available varieties are relatively distinct, especially if you know what to expect. When growing logs outside, it is best to pick your mushrooms earlier than later to avoid munching on the odd insect that likes mushrooms, too!