Basics of Growing Mushrooms
How Do I Grow Mushrooms?
To answer a question with another question, I suggest you first ask yourself which mushrooms you’d be interested in growing!
As you may or may not already be aware species of cultivated mushrooms are lumped into one of two groups. On one hand we have our organic woodland cleanup crews consuming various woods & wood wastes converting lignin into energy to proliferate & ultimately (hopefully) produce mushrooms. These lignicolous fungi, we describe as lignophiles, otherwise known as wood loving mushrooms. On the other hand we have our dung loving coprophilic fungi aka coprophiles such as Agaricus sp., Psilocybe sp. & many others. Other areas of cultivation not directly related to gourmet mushrooms include medicinal use of parasitic fungi like Cordyceps sp. & fermented foods like Red Yeast Rice or Tempeh. As these are not the most commonly grown, the discussion will not focus on them, but these important fungi needed to be mentioned nonetheless! Whichever mushroom interests you, continue reading to learn more about how to grow your own mushrooms!
What Is A Mushroom Substrate? What Is Mycelium?
Have you ever been digging in the mulch, and been curious to the white growth which seems to cover any surface beneath the mulch which the sun does not actually touch? This is what’s responsible for the mushrooms that may or may not have appeared in the same mulch bed, a network of mycelium.
When mycelium is growing, the term mushroom growers use to describe this is colonizing or colonization (#ColonizeThePlanet!) and the entire food source of this mycelium is considered its substrate. For our example above, the mulch bed is our substrate (and yes, people artificially grow things like Wine Caps and other mushrooms in their own wood beds at home) but for most mushroom growers, you’ll be working with a bagged substrate, a substrate in a container, jar or other vessel, outdoor logs (real trees!), or any combination of indoor or outdoor beds.
For the home grower, mycelium is generally procured in the form of a liquid culture, colonized petri-dish or as fully colonized mushroom spawn. Mushroom spawn is simply (in most cases) grains which have been colonized with a pure culture in sterile conditions. It sounds simple, but in practice creating clean spawn proves to be a challenge to some home growers, but is not impossible. I will not detail producing clean spawn at this time, there are many ways to skin that cat and spawn making requires a dedicated, perhaps multi-part article! Stay tuned for more on that!
What Do Mushrooms Grow On?
Mushrooms are now being grown on all types of interesting materials and wastes from coffee grounds to cardboard, from stuffed animals and furniture to coco coir and many things in between. More conventional to the western home mushroom grower, hardwood sawdust, straw, brown rice flour, CoCo Coir or manure are used (sometimes in combination) and there’s a lot of innovation which continues to propel home growing into more accessible spaces than ever (Uncle Ben, is that you?) and while I can’t detail them all, I encourage you to consider first the principals of growing mushrooms, not necessarily the application. There are a million ways to skin a cat, this applies to mushroom growing in absolute terms and is one of the reasons I was first attracted to growing mushrooms in the first place!
What Do Mushrooms Need To Grow?
In the most basic terms (without considering any specific species) mushrooms, like any other living organism, need food, water & air. More specifically, certain conditions must be met in order for mycelium to produce a fruiting body which we describe as a mushroom. Some more aggressive species have relaxed fruiting conditions and are near impossible NOT to fruit, whereas other mushrooms are far more particular requiring special attention to these parameters at certain phases of growth to see results. Those conditions (in no particular order of importance) are as follows:
How To Grow Wood Loving Mushrooms
Speaking again in general terms, with no regard to a specific species (unless noted), growing wood loving mushrooms is generally a more forgiving exercise as opposed to growing coprophilic mushrooms. Wood loving gourmet fungi grow happily (in most cases) on hardwoods, and most commonly for the home grower in the form of Hardwood Fuel Pellets (HWFP) which can be found at most big box hardware stores. These pellets are generally comprised of 99% OAK placing them in the compatibility range for nearly all wood loving gourmet mushrooms. These pellets are compressed with heat & pressure, and are generally clean enough to use by themselves by simply adding the right amount of boiling water to a bucket, covering with a lid & allowing to cool, spawning immediately.
Supplemental nitrogen nutrition is commonly added to HWFP substrates using wheat bran, cottonseed hulls or soybean hulls.
SUPPLEMENTING HWFP/SAWDUST SUBSTRATES IS NOT REQUIRED, you will see better yields than otherwise but an increased contamination risk is present. Sterilization is required for supplemented substrates.
Different formulations of nitrogen supplement for growing mushrooms exist for home growers, but in general you can expect to use the following supplement rates, some notes are provided and if you’re not sure I encourage you to do research on the species you are growing before committing to growing it! Supplement recipes as follows:
- Wheat Bran: 20% for most gourmet mushrooms, 5% for Shiitake
- Cottonseed Hulls: May be used up to 50% for Pleurotus sp., Hericium sp., no experience with Shiitake. (Email me if you can comment on this!)
- Soybean Hulls: 50/50 mix HWFP & Soybean Hulls = Masters Mix, high yielding substrate for Oysters.
- Beet Pulp: 10-20% for Pleurotus
It’s worth noting that simply using high (grain) spawn ratios also adds nutrition, expedites spawn runs and increases chances of success for new growers. I think adding extra spawn for these reasons instead of adding supplement is a wise choice for new mushroom growers.
Once a substrate is selected, it is either pasteurized or sterilized, inoculated with clean and happy mushroom spawn, and allowed to colonize.
Once the substrate is colonized, it is generally provided humid fresh air & pinning begins. Once pins have formed the mushroom fruiting body matures and as they used to say at the guillotines, ‘OFF WITH THEIR HEADS!’. Rinse & repeat, species depending. The record for me before I stopped counting was 10 harvests with a single Pink Oyster mushroom bucket grow, it was just straw!
Growing Coprophilic Mushrooms
Coprophilic mushrooms grow best on pre-digested grasses (compost, manure etc…) and home growers have discovered that Psilocybe cubensis mushrooms will even grow on and fruit from grains such as brown rice, and even coco coir substrates. While other growers may use straw, some will use manure and some even mix the two among other things, you have some flexibility when choosing your substrate, but your local materials will more than likely be your most influential factor.
Manure where I live is basically free, others may have free or cheap straw, it’s worth noting while discussing straw that composted straw works a hell of a lot better than freshly baled straw. Coconut coir with added vermiculite is a popular choice due to low likelihood of contamination and ease of hydration through first hand experience with this substrate leaves a lot to be desired compared to straw, with a good vermiculite & manure blend being tried, true and my preference.
The approach with dung loving mushrooms is generally the same as with lignicolous fungi. Bagged substrates, beds or vessels are filled with pasteurized substrate which has been cooled for spawning, and inoculated with clean happy spawn. The substrate is allowed to colonize, sealed (with some but very restricted airflow to prevent surface molds) to keep CO2 levels high and prevent premature pinning.
Once the substrate is completely colonized, humid fresh air is introduced and CO2 levels may or may not be managed to initiate pinning, at which point fresh air levels are generally increased to promote the development of the mushroom fruiting body.
Species, scale and geographic of the grower depending, these parameters and approaches to managing them vary but remember, the underlying principles are the same. We’re just managing mycelium, nurturing it to the point it’s ready to fruit and then enjoying the fruits of our labor, pun intended.
To summarize the process:
- Spawn Making
- Substrate Preparation (Pasteurization/Sterilization)
- (8) Rinse & Repeat
Some crops are able to be fruited immediately with no soaking or hydration required, other species require the substrate to be soaked, watered or otherwise hydrated to produce second, third or more harvests (flushes) successfully. Not all mushrooms will produce more than one harvest.
Myc, I’m Still Lost, Just Tell Me Where To Start!
Again, another question to answer this question! Have you considered whether you want to start from scratch making your own spawn (Intermediate), using spawn to make your own substrates (moderate) or using a ready to fruit kit (easy) for your first time?
All this jazz about spawn and mycelium may be overwhelming to someone who just wants to dig in and get something growing without spending tons of money or effort researching, and that’s great! Some folks learn best this way, and many great vendors offer pre-colonized substrates that are ready to fruit. My specialty at the time of writing this article is ‘7lb Lion’s Mane kits‘, check /r/MycoBazaar on Reddit to see other vendors and their offerings.
If you’re hoping to start from scratch, it’s not that hard so long as you have a still air box, laminar flow hood or other sterile working environment! If you’re not sure what these things are, check out the ‘Mushroom Growers Wiki’ on /r/MushroomGrowers! If you’re taking this route you have two approaches. You can purchase a liquid culture or a colonized agar plate (check out @Kaizen_Mushrooms on IG) and inoculate sterilized grains with your culture. From there, once the grains are colonized with healthy & happy mycelium, you’ll be able to inoculate a substrate per the needs of the mushroom you’re growing.
Whichever route you take, remember, you’re a mycelium manager, you’re the boss – don’t be intimidated or overwhelmed, and if you do find yourself feeling stuck or having questions, I’m just a comment, DM or email away!