The Middle School Mushroom Project


The Mysterious Mushroom 


One of the mysteries about mushrooms is the fact that they are not plants and therefore are not vegetables. They are their whole own category of life and are actually more closely related to humans than plants!


One factor that demonstrates this is that they are not photosynthetic; they must obtain their food from pre-existing material, just like us. It was a pretty amazing revelation for me when I really stopped and thought about how I was eating a completely unique lifeform. It’s a hard habit to break though, not calling them a vegetable. And instead saying they are my favorite life-form to cook with. Maybe one day! 


What are mushrooms?

First a little background information to understand this beautiful life form a little better.


A mushroom is just one part of one class of fungi, and what you see above ground is far from the whole organism. This cap-and-stem structure that we know so well is the reproductive structure, the fruiting body of a fungi.  Just like a tomato plant produces tomatoes as its fruit in order to disperse seeds, the agaricomycotina class of fungi produces mushrooms as its fruit in order to disperse spores (the equivalent of a seed).


Most of the story for a fungus happens underground where a whole network of thread-like mycelium is slowly making its way through the soil searching for (and consuming) nutrients. When the right conditions line up, the mycelium produces this fruiting body which in turn produces a ton (usually millions, sometimes even billions) of spores. The wind and animals disperse the spores, start new mycelium. Fungi are the drivers of so much of what happens in nature, breaking down material, helping plants with nutrient uptake. The mushroom is how this one class of fungi regenerate, how they continue living.


Mushrooms are not one of the first things that comes to mind when you think of growing your own food. While it can be a little tricky, there are many reasons to try it out. The first is that trying new things is fun, and the second is that they’re delicious. On top of that, it provides variety to gardening, as they need different conditions (you won’t have to worry about them getting enough sun) than other things you may grow. Mushrooms also provide a great variety of nutrition that differs from plants. So, put your mushroom caps on, and have some fun-gi!  


How to grow mushrooms?

Mushrooms are easier to grow than plants in some ways, and a little trickier in others. With urban gardening, the lack of sunlight is often a problem. For mushrooms, the hardest parts are figuring out the right substrate from which they will grow, as well as providing consistent conditions. They require an even, warm, temperature as well as quite a bit of moisture once they have spawned (once the spores are on a substrate). Somewhere like a garden shed or basement could work, or even under a sink depending on the temperature of your house. 


As mushrooms cannot create food from light (the miracle of plants being able to do this never ceases to amaze me!), the substrate in which they grow must provide them with the right mix of nutrients. These include sugar, starch, lignin, fats, protein, and nitrogen. There are multiple substrates that have been used for successful growth, and they range from simple to complex.


Some mushrooms grow better on a certain substrate, and the ideal conditions for every mushroom will be different. You can purchase spores from one of many companies that produce them. Pick a reputable company with a short shipping time to get the spores at their freshest.


Other basics include keeping a clean environment, so the growing mushrooms don’t get contaminated, maintaining a high moisture level (but no standing water), and maintaining some air flow.  The humidity can be kept high by routinely spraying the substrate with water. 


Substrate Options:

The simplest option is to buy a growing kit which will provide you with the substrate and spores as well as instruct you on exactly what to do. This can be a great way to get a hang of the process before coming up with your own design. 


When it comes to how to grow your mushrooms, we will be talking you through 3 main methods.


METHOD 1: Compost

This is the most common substrate for home-growing is compost. I will go into some detail here about the process of growing.


Step 1: Getting the compost

The compost composition will vary with each type of mushroom. If you are a confident compost maker, try using your own and see what happens! If you don’t want to get into making your own, just buy a good quality compost from the store. One with horse manure is a safe bet for mushrooms. 


Step 2: Spawning

Fill a plastic tray  with about 10 cm  of this compost, and then distribute the spores on top. Mix it well and cover with a damp newspaper (but make sure a little air can still get in). Within 2-3 weeks, you should see the mycelium starting to grow. This will look like a bunch of white threads covering the surface. The temperature for these first weeks needs to be kept around 23°C/73°F. 


Step 3: Casing

Once the surface is covered with the mycelium, remove the newspaper, wet well and then cover with another layer of a different material, which is called the casing. This is the layer on which the actual fruit bodies will grow.


The casing layer does not need to contain nutrients, as the fruiting body is produced entirely from the mycelium which is getting nutrients from the first compost layer. Look for a clay-loam soil or mix soil and sawdust  (this is a step that will vary depending on species of mushroom). At this point, keep the temperature at 23°C for the first five days, and then it is best if it can be lowered a little bit each day until the initial mushrooms pop up. 


Step 4: Harvesting

Mushrooms will be large enough to harvest after about three weeks, and you will be able to keep harvesting them for up to 60 days depending on the species.


They mature in cycles, so about once a week there will be mature ones ready for the picking (breaking off. If possible at this stage the temperature should be lowered by about 10°C.