Growing mushrooms from a kit is fun, educational and nourishing, but it doesn’t meet my definition of sustainable. To turn my kits into something sustainable, I am experimenting with naturalizing the mycelium so that I can create an outside oyster mushroom garden.
One of the ideas that I obtained from Paul Stamets’ book, Mycelium Running: How Mushrooms Can Help Save the World was the idea to grow mushrooms using the stems of harvested mushroom between sheets of damp, unpainted corrugated cardboard from shipping boxes. Through his experiments, he found that he can successfully grow spawn for many kinds of edible mushrooms using the basal rhizomorphs where the stem was connected to the nurturing mycelium. Using his ideas and modifying them to the materials I have available, this is our latest experiment:
First we tore up cardboard boxes and laid them in layers in a plastic box to soak in warm water. The warm water softens up the fibers, making it easier for the mycelium to establish itself. The growing mycelium from our kit was conditioned to use hydrogen peroxide, so we added a half cup of hydrogen peroxide as well. After carefully cutting away the lower stems from the mushrooms we harvested, we placed them gently between the damp, softened sheets of cardboard. We were careful to keep the rhizomorphs (mycelial strands attached to the stems) intact. Afterwards, we misted the pile of cardboard daily to keep the cardboard damp and watched as the white strands began to appear between the edges of the cardboard layers. When we noticed the white strands appearing on the top sheet of cardboard, we simply added more layers of soaked cardboard. Within three or four weeks, we could see mycelium had spread throughout the stacks of cardboard.
The tall stack of cardboard was getting harder to manage in the playroom/laboratory, so we added more sheets of damp cardboard to the stack and buried the stack of inoculated cardboard in the middle of a mixture of damp sawdust and coffee grounds. There is about one inch of damp sawdust above the cardboard and several inches below it. (Living with a prolific and talented woodworker means I always have a wonderful supply of wood shavings and sawdust.) We made everything damp before we added the ingredients together because allowing mycelium to dry out makes it difficult for it to thrive or even survive. When we notice the entire plastic container has been successfully colonized by the mycelium, we will transfer it outside to a bed of wood chips. I even have a place chosen, in the shady, cool area below our large weeping willow tree.
You do not need to use a kit to try to grow mushrooms from stem ends. You can also use wild mushrooms you discover and collect, the way ORJ described in the comments of my previous entry. Just don’t let the stems dry out and be careful to keep the fluffy stem base along with the stem. The stems from mushrooms purchased in the grocery store probably will not work because the stems must be fresh to regenerate.
Here are a few photos of the process:
Here is a photo of the mycelium spreading through the layers of cardboard. I apologize that it isn’t clearer, but the cardboard is all buried now and I cannot take a better one now.

And the final product, the cardboard is just under the damp shavings. At one end, I put some cardboard layers upright, to see if the different orientation makes a difference to the mycelium’s success:

-- "To forget how to dig the earth and to tend the soil is to forget ourselves." M. Gandhi
















11 comments so far
daltxguy
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posted 436 days ago
Now that’s mycellium running!
Well done Robin!
Now that you’ve managed to propagate the mycellium successfully, doyou require to do anything to force it to bloom. From personal observation, most mushrooms show up here in cooler weather.
-- Disobedience is the true foundation of liberty. The obedient must be slaves. - Thoreau
justjoel
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posted 436 days ago
Too cool and fun!
-- There's a box?
MsDebbieP
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posted 436 days ago
intriguing
I can picture you guys with your white lab coats and magnifying glasses!
-- - Debbie, SW Ontario Canada (USDA Hardiness Zone: 5a)
Bon
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posted 435 days ago
Looks like you’re becoming quite the shroom farmer there Robin.Good luck with all your experiments.
-- Bon,Hastings,Ont.....zone 5a....Always room for one more
Radicalfarmergal
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posted 434 days ago
Thank you for reading about our experiment and all your wonderful comments.
Steve, my understanding is that mycelium produce mushrooms when all the optimal conditions (primarily sufficient water and within an acceptable temperature range) are present and the mycelium has stored up enough energy to produce the fruit. I found this educational website about mushrooms that shared this cool information on why mushrooms grow so quickly:
“Plants and animals grow through cell division – to get bigger they have to produce more cells. Cell division is relatively slow and requires a lot of energy. The mushroom body also grows by cell division. However, the mushroom fruit does not grow by cell division. Just about as soon as it starts to develop, a mushroom has almost the same number of cells that the mature mushroom will have. The mushroom increases in size through cell ENLARGEMENT! This means that the cells can balloon up very rapidly. Very little energy is required, basically the cells just enlarge with water. So a mushroom can increase in size as fast as water can be pumped into its cells. Almost overnight a mushroom can go from a pin head to a large mushroom.”
The website has more fun information if you are interested in reading more about experiments with mushrooms.
-- "To forget how to dig the earth and to tend the soil is to forget ourselves." M. Gandhi
daltxguy
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posted 434 days ago
Robin – thanks for that ! mushrooms are fascinating. So how do you encourage your mycelia to grow mushrooms? or does it just happen?
If I get a chance I will photograph a particular kind of mushroom here which demonstrates the inflating cells very well. It grows ( well maybe it’sjust the fruiting body?) on the surface of the ground and on a normal, hot day, it looks like a cow pattie – but there are no cows there. When it rains, it swells up and then looks like seaweed washed up on shore! I have no idea what it is called and I’ve been stepping on it for a long time before anyone even pointed it out to me!
-- Disobedience is the true foundation of liberty. The obedient must be slaves. - Thoreau
Radicalfarmergal
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posted 434 days ago
Steve, I am not an expert by any means, but I think the best strategy is to give the mycelium enough time to gather up sufficient energy and then provide the right conditions for fruiting. Whenever the mycelium is disturbed (crushed, tilled up, dried out) it has to spend energy to reestablish itself. The less it is disrupted, the more quickly I think it will fruit.
Outside I generally see fresh mushrooms in the spring or autumn. They usually emerge quickly after lots of rain and when temperatures are fairly cool but definitely above freezing. I don’t know if this batch of mycelium will have gathered up enough energy to fruit this spring. but I will be happy even if they don’t show up until next spring. When growing mushrooms inside the house, you can measure the temperature and humidity and make changes when you need to, but outside I will be dependent on observation and nature. The variables I can control are the location (the shady, moist area under the weeping willow tree), the food (wood chips, wood shavings, logs, etc.) and moisture (irrigate if precipitation is lacking) supply. I know from my readings that mushrooms beds and inoculated logs are sometimes covered by tarps to keep the moisture high where the mushrooms are growing. It will be a learning adventure.
I am very curious about the mushroom you describe. Yes, please take photos of it when you see it.
-- "To forget how to dig the earth and to tend the soil is to forget ourselves." M. Gandhi
mmh
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posted 408 days ago
I recently purchased oyster mushroom kits made with recycled coffee grinds from a young entreprenure at the Philadelphia Flower Show. They are working out of California. No flush of mature fruits yet, but they are active.
-- A weed is a plant that is growing where it was not purposefully placed by human hands.
Radicalfarmergal
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posted 408 days ago
mmh, is your kit from the Back to Roots company? They have such an interesting story behind their company. Good luck with your mushrooms! I hope you have as much fun as we are having.
As a quick update, our indoor kit is starting its third flush! This one is much smaller than the previous two, but I am sure they will taste as good. As for our mycelium in cardboard experiment, I can see from the bit of vertical cardboard that is above the shavings/coffee grounds mixture that the cardboard has been thoroughly colonized by the mycelium. We check on the box periodically to make sure the substrate is still damp but other than that we are leaving it alone as it gathers energy.
-- "To forget how to dig the earth and to tend the soil is to forget ourselves." M. Gandhi
Radicalfarmergal
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posted 320 days ago
I just wanted to let everyone know that our cardboard-mushroom experiment is working! They are still tiny, but I am so pleased to see that our experiment worked.
-- "To forget how to dig the earth and to tend the soil is to forget ourselves." M. Gandhi
MsDebbieP
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posted 320 days ago
that’s wonderful!!
Another A+ :D
-- - Debbie, SW Ontario Canada (USDA Hardiness Zone: 5a)