Mushrooms Ate My Homework...

Mushrooms eat the weirdest things. Had I known when I was a kid how voracious certain edible mushroom species can be, I surely would have fed them my homework... mushrooms are, after all, amazing recyclers. They are particularly good at breaking down difficult-to-digest carbon sources like paper, cardboard, logs, wood chips, toilet paper rolls, shredded office reports, old books, oil, old furniture, straw, twine, coffee and tea, twigs, hard insect exoskeletons, sawdust, grains... some species can even munch through certain plastics! They are exceptional recyclers being some of the only members of the underground soil world that can break apart lignin, the difficult-to-digest compound found in wood. It's even possible to grow edible gourmet mushrooms indoors right in your kitchen, on the counter or under the coffee table! Yes. I admit it. I am that person who might occasionally have mushrooms growing as centerpieces in the dining room... only OCCASIONALLY, mind you!

There are many creative ways to grow mushrooms indoors, but let me share one I particularly enjoy. This step-by-step strategy is for transforming humble paper recycling (could include your homework...) and used coffee filters and tea bags into a mycological kitchen adventure! At the end of the experiment, you will have several harvests of Oyster Mushrooms and will have turned your old cardboard, homework, and coffee and tea leftovers into a good quality slow-release fertilizer and soil amendment.

Step 1. Choose your spawn. Mushroom spawn is a material - usually grain, sawdust or wooden dowels - that is inoculated with the species you want to grow. I choose grain spawn here as it had a lot of nutrition to support mushroom growth. I typically buy a mushroom-growing kit or a supply of grain spawn sold locally by a local mushroom supplier (more farmer's markets have mushroom growers these days!) or order them online (mushroom supplier resources listed below). This is the fun part to choose what kind of mushrooms you want to grow. Oyster mushrooms are an excellent choice. They a diverse species that can easily colonize many different types of materials you might add, plus they come in SO many colors : light blue, soft gray, brilliant yellow, hot pink, and tan.

Step 2: Layer the Spawn and Coffee/Tea/Shredded Cardboard into your Box. Take an empty cardboard or cereal box(s) and add several inches of mushroom spawn to the bottom. Then put in additional layers of materials mushrooms like to eat (shredded paper, cardboard, straw, finished coffee filters and tea bags... perhaps your homework!). Note that these added paper materials should not have any competing organisms on them that will battle with your fungi... the most likely culprit being common blue-green-black molds on old paper or musty smells from old cardboard in a damp basement. An even better option is to soak the paper you will add to your mushrooms in a pot of boiling water for a few minutes, remove it, let it cool, THEN add the handfuls of wet paper alternating with mushrooms and tea/coffee to your cereal box. I usually fill it about 2/3 of the way, leaving plenty of room to add old tea bags and coffee as I use them in the following days...

One of the reasons I love to use leftover coffee and tea is that boiling water is poured on or through it anyway! You essentially sterilize this most excellent growing medium as you use it. You can also save up a small supply of used coffee filters and tea bags in the freezer to keep it free from mold while you wait for your spawn to arrive.

Note: In this particular set of pictures, I had WAY more spawn that would fit in a single cereal box. Two options: make more cereal boxes as long as you have stuff to feed the mushrooms OR just reseal the spawn bag and slit "X" shaped cuts into the surface to sprout the mushrooms directly from the bag. You can always add more materials (like homework!! Ha ha!) to the original spawn bag.

Step 3: Keep Moist and Carry On! Keep adding "food" to your mushrooms like coffee and tea and moist paper to your cereal box as you have it until your box is full. The mycellium - the white threads or fuzzy white growth which is your edible oyster mushroom - will slowly cover the food you give it as it establishes. Your goal at this point is to keep your young mushrooms moist (but not sopping wet) and undisturbed. I put mine in a clean plastic box in the kitchen with a clean produce bag over the top. The produce bag in this picture happened to have tiny holes in it which was great for air circulation. Believe it or not, fungi breathe oxygen just like we do, and if they don't quite get enough the mushrooms will be thin and spindly. You can mist the inside of the bag with water to keep moisture high.

Notice the little blue mushrooms popping out of the cardboard at the base of the cereal box. It doesn't take long for them to pop up as long as they have all they need : moisture, air, and plenty of tasty cardboard ... or homework! eh-hem! The bag to the left already produce a flush of mushrooms which was harvested (note the leftover stalk on the left side of the bag).

4. Harvest the bounty: Once the mushrooms have grown big enough, but before their caps splay up and outwards (a signal they are going past their prime and going to produce spores), harvest the entire batch of your tasty young mushrooms. Unfortunately, you can't pick and choose your mushrooms one by one, but must harvest all at once. The harvesting sends a signal for the mushrooms to stop producing (at least as I understand it!), so harvest completely when you do!

5. Rest, Re-soak, and Repeat! Once your mushrooms have been harvested, I usually give them a week or two of break to rest and reset. Then I soak the entire cardboard box by submerging it in water to rehydrate for a few hours, or put it in a small tray of water to soak up the water and jumpstart another flush of mushrooms. You can keep feeding them coffee, tea and cardboard as is needed and as there is room, but that is optional, and not required for another flush of mushrooms.

6. Retire Them to the Garden (optional): Once the cereal box is full and the mushrooms seem to have finished (often 2-3 flushes), there are several options. If the box hasn't entirely been eaten, you can add it all to the compost for an awesome soil-building fertilizer. Or break apart the leftover substrate of "homework-coffee-tea-grain" remains and sprinkle on the garden bed or work lightly into soil as a slow release fertilizer to feed your soil and your plants. OR... jumpstart even more mushrooms by adding the cereal box to a large pot in a shady corner of the garden or yard and feed it all sorts of leaves, old twine, wooden labels, shredded leaves and twigs, diseased plants, weeds and old plant matter. Sometimes you will be surprised at the voracious nature of your mushrooms and how they come back in full force. Here's a picture of my mushrooms... they seem to love all the outdoor attention. Notice the extra sunlight has turned these young blue mushrooms brown as they get older. You can even see the cereal box still peeking out through the tangle of tasty carbon sources... yum!

Troubleshooting: One of the reason I love oyster mushrooms is that they are recognizeable, dominant and tend not to let other wild fungi colonize. Yet once you move them out into the garden, please be aware it is possible (though very unlikely) for a wild non-edible species to colonize. Use your judgement and don't eat any species you can't positively identify. The most likely fungi you will see when growing oyster mushrooms is likely blue-black mold which is the most common mold found in households (... the lower order fungi that is found so often in refrigerator produce and food like bread once it has gone bad... ). If you see tiny specks of this mold on your coffee filters, tea bags or cardbaord, just remove it or dab it with rubbing alcohol to reduce competition with the higher order fungi (oyster mushroom!) that you are trying to cultivate. Sometimes oyster mushrooms can be so aggressive, they will surround any blue-black mold that shows up and slowly do battle... decreasing their hold on the cardboard box until they disappear. Yet it's always nice to help them along and remove the mold if you happen to see it.

Mushroom Resources:

*mushroom growing suppliers (including the ones listed below) often have amazingly well-written short guides on their websites for the mushrooms they recommend for home mushrooms growers... check them out!

Fungi Ally (MA): spawn, growing kits https://www.fungially.com/

Fungi Perfecti (WA): different types of spawn, growing kits and instructional materials. https://fungi.com/

Gourmet Mushrooms (CA): spawn including morels, grow kits: https://gmushrooms.com/

North Spore (ME): spawn and growing kits https://northspore.com/

"How to Grow Mushrooms from Scratch: A Practical Guide to Cultivating Portobellos, Shiitakes, Truffles, and Other Edible Mushrooms” by Magdalena and Herbert Wurth