The Pennsylvania State University, College of Agriculture, Extension Service, University Park, Pennsylvania
Mushroom farming consists of six steps, and although the divisions are somewhat arbitrary, these steps identify what is needed to form a production system.
Step-by-step process: How to grow mushrooms outside with log cultivation
- Cut logs and gather materials. First step is to gather all materials you will need for growing mushrooms outside. Order sawdust or plug spawn here. If you are using sawdust spawn, you will also need to purchase a palm inoculation tool. If you are using plug spawn you will need a hammer. Cut the logs being used for cultivation between December and March.
- Drill holes into the log for the spawn to go into. The holes should be about 1 inch deep and spaced 6 inches apart in the row. The log should be rotated 2 inches to start the next row, drill all the way around the surface of the log with 2 inches in between rows and 6 inches in between holes in the row. The rows can be off set creating a diamond pattern.
- Fill the holes with either plug or sawdust spawn. If using the plug spawn place each dowel on the hole and hammer it in until it is flush with the surface of the log. If using sawdust spawn, fill the palm inoculator with spawn to create a dowel-like structure and then hit the inoculator to place it into the hole. Be sure the hole is completely filled with sawdust spawn. Sometimes it can look like it is full but really there is only a small amount of sawdust spawn inside. You can use a small stick or allen wrench to ensure the sawdust spawn is fully compacted.
- Once the holes have been drilled and filled the last step is to wax over the holes. This ensures the sawdust spawn has a moist and safe place to grow. The bark of the log acts as an armor, keeping unwanted fungi out and moisture in. By waxing over the inoculation holes the sawdust spawn will not dry out as it grows into the log. Other fungi with spores floating around in the air will also not be able to get into the log to compete with the shiitake mycelium.
- Lastly, stack the logs in a shaded area. Conifer works best for the year-long incubation of logs. Logs that are inoculated in April will begin their fruiting period the following June. Be sure to maintain moisture around 45% during the incubation period. It is critical to water the logs every 2-3 weeks if there is no rainfall. To water, either soak for 4-5 hours (although this can be very labor intensive) or place a sprinkler on for 4-8 hours.
Additional resources on how to grow mushrooms outside
One of our favourite ways to grow mushrooms is to tuck them in, here and there and everywhere around the garden.
A little bit here, a little bit there. Enokitake mushrooms love growing as the base of currant bushes, for example. Saffron milk caps are happiest (and only grow, infact) under pines.
There’s lots of ways to get things growing. You could mix up a slurry of porcini mushrooms (old ones that weren’t good enough to eat) and try inoculating a few local oaks, like our friend Speedy (or Paul Ward, as his Mum calls him) recently did.
Or you could make a mushroom garden bundle (also an innovation of Speedy’s) – which is a gorgeous way to bring new life to un-shroomed corners of your patch…
Making a Mushroom Garden Bundle…
Speedy showed us how to make these at our place last weekend, and they’re such a great idea – an inoculation bomb, if you will – think seed balls, but for mushrooms…
You will need –
- Home-made or bought Mushroom spawn, or a few fresh mushrooms of your chosen type may work, at a pinch
- Un-treated hessian or cotton cloth
- String made of natural fibres
- Any bits of moss or root cuttings you wish to add
- A bucket of water
Roll up spawn or mushrooms in wet hessian to make a kind of hessian sausage. Then curl up into a spiral bundle, and secure with natural string.
In the middle you might like to tuck in a root cutting from something like comfrey, a great forest garden groundcover, and maybe some moss or other support species around the edges.
Then dunk in a bucket of water and leave until it is all well soaked.
Then take out of bucket, shake off excess water, and place under a particular type of tree, or on some wet woodchip or… whatever makes sense for that species.
Good mushrooms to try in this technique would be saprotrophic ones, like:
- Wood Blewits
- King Stropharia
- Oyster Mushrooms
Whichever technique suits you best, do your research, get the ingredients you need, and give it a go.
The results will not be immediate, but over the coming seasons, your garden should reward you with flushes of tasty mushrooms to supplement your seasonal produce.
Want to learn to grow mushrooms? We run 2 day intensive courses in Sydney (and now Hepburn, VIC!) which are packed full of hands-on learning and cultivation supplies too – check them out here.