Mushrooms farming has become much more accessible in recent years than ever before. Brilliant mycologists like Paul Stamets have been leading the way in helping the rest of us to understand various mushrooms around the world. This has made it incredibly easy for the rest of us to learn his techniques! Hopefully this extensive guide to growing oyster mushrooms will help you cultivate your own delicious crop. Read on to learn how!
Growing Oyster Mushrooms is Ideal for Aspiring Mycophiles
There are many types of mushrooms you can grow at home. In this article, we’ll focus on oyster mushrooms (Pleurotus). Oysters are the most forgiving mushroom to learn with, and can be grown in the largest selection of growing mediums. This makes them the perfect mushroom to begin your fungus-farming experience.
You can buy mushroom growing kits from many excellent websites, such as Fungi Perfecti. They have kits for several edible varieties, as well as medicinal mushrooms. These kits are very easy to use, and can help you learn all about mushrooms’ different growing stages.
If you want to take a step further, you can order bags of spores (sometimes also called mushroom spawn). These enable you to inoculate your own growing medium at home for larger scale production. We’re going to discuss how to grow your own mushrooms in three different ways. No matter what, you should be able to find a way to grow these delicious mushrooms in your home or garden.
First, we’ll talk about the simplest way of growing oyster mushrooms at home: an already spawned, ready-to-grow kit.
There are many websites that sell mushroom-growing kits, though I personally recommend Fungi Perfecti. They offer a wide variety of kits, spores, and tools needed for successful mushroom growing. Kits usually cost about $20-$35, depending on where you purchase them.
These growing kits are super easy to use! As long as you can provide a space with ample amounts of indirect sunlight and water, you’ll soon enough have some delicious mushrooms to eat. Typically, each kit will grow about 5 pounds of mushrooms.
Usually, these kits come with a clear poly bag liner and a black bag (with holes) full of an inoculated growing medium. Don’t open the black bag! First thing you’ll want to do is stand the black bag upright inside the shipping box. This will help your mushrooms grow in their natural, shelf-like growing style.
Water the black bag as soon as possible: sprinkling or spray misting works best for this. Don’t over water, as standing water in the bottom will cause rot and contaminants to grow.
Next, pull the clear bag liner over top, leaving the top open enough to let air in. This will allow for your mushrooms to breathe, but will not dry them out as they grow. Air circulation is very important as lack of proper air will cause you to grow long stringy mushrooms. The clear liner will also help raise the humidity around the fruiting mushrooms in the coming days.
Small oyster mushrooms will appear in 3-7 days, at this point increase your watering to 2-3 times daily. At 7-14 days, mushrooms will have appeared and will double in size every day.
Harvest your mushrooms when they stop growing, or when they get large and begin to flip their cap upward (like a reverse umbrella.) Simply twist the mature mushrooms to pull them free. Cutting them off is also acceptable, but can leave a stump that may cause rot and therefore inhibit the following “flush” (a subsequent mushroom crop.)
Although some oyster mushrooms species only have 1 crop, you should be able to get up to 3-5 flushes. The 1st and 2nd will always be your best harvests. After your kit is done producing, you can cut open the black bag and compost the contents.
Now, If you want to grow much more than what a mushroom kit can offer, try one of the following methods. But first, here are some basics:
Substrate (Growing Medium)
Out of all the gourmet mushrooms to grow at home, oysters are the least picky about what they’ll successfully grow in. They’ll happily grow in most hardwoods and wood by-products (paper, sawdust). They’ll also grow happily in cereal straw, corn cobs, coffee grounds, cottonseed hulls, soy pulp… the list goes on and on. These are just a few easy-to-find options.
Proper substrate sterilization is essential to successful mushroom growing! Sterilization is needed so that only the mycelia that you want to grow will take hold in your growing medium. Improperly sterilized hay, logs, etc. can hold contaminants. Bacteria and other fungi will quickly spread into your growing medium. These contaminants use up your medium’s nutrients and weaken your mushroom spawn’s chance for a good start.
Luckily, sterilization doesn’t have to be a thorn in your side. For small substrate batches, a good sized pressure cooker will work fine. You’ll need a pressure cooker that can maintain a pressure of 15psi, which allows for a steam temperature of 250℉. This temperature will eliminate all plausible contaminants and help you rest easier.
A quick warning about using pressure cookers:
– Make sure you fully understand how to use your pressure cooker beforehand. It will create a lot of pressurized steam and this could become hazardous quickly if done incorrectly.
– Use a proper amount of water: too little amount of water will burn up your substrate batch.
– Check the seals on your pressure cooker as well (some don’t have a rubber seal at all.) A good seal on your pressure cooker is important to keep proper temperature for the right amount of time.
Cleanliness is Key
Wash your hands often! Clean off any of your tools with alcohol. Keep in mind where contaminants could come from and try to stop them before they ever enter the area you are planning to work in.
One problem you may have to deal with is Sciriad and Phorid flies. They’re attracted by the mushrooms’ spore release. Leaving a dish of apple cider vinegar open to the air can deter a few, but rarely eliminates all the flies.
Three other options that I’ve heard of mushroom growers using (but haven’t yet tried myself) are:
Introducing nematodes into their growing area, spraying growing areas down with neem oil, and using smoke to suffocate the flies.
If you find that your mushrooms are being bothered by more than just a few of these pesky flies, I’d suggest conducting your own research to see what fits well with your situation. There are many excellent forums about mushroom growing on the web.
Growing a Mushroom Bed Outdoors
Unlike a controlled indoor environment, we’re at the mercy of nature when growing outdoors. Plan accordingly to your region’s temperatures, average humidity, and rainfall to greatly increase your success rate. Remember to include the 2-4 week timeframe from spawning to to first flush of mushrooms when planning out your region’s perfect time to grow.
Where I live in central Arkansas, spring and fall are the best times for growing oyster mushrooms outdoors. Lower temperatures are more favorable, and our springtime rains help keep the ground moist. If you want to try to grow in the summer or live somewhere that stays much warmer, try a tropical variety such as Yellow or Pink oyster.
First, find a place outside that will get plenty of rain and moisture, but not too much direct sunlight. Choose somewhere in the shade near other plants, this will help keep your humidity level a bit higher.
To prepare your mushroom growing bed, you will first want to lay down a piece of cardboard to stop weeds from growing. Next, you will want to evenly spread a 2-3 inch layer of straw on top. One of the best things about growing outside is that you do not need to pasteurize your straw! (You can also add any other substrate you want to use, such as hardwood chips.)
The next step is to crumble your mushroom spawn onto your straw bed at a rate of 5-10%. This means that you want to use 5-10% the weight of what your straw would be wet. You don’t have to be exact with this percentage and with practice, you’ll learn how to gage the proper amount of spawn.
Continue adding layers of straw and spawn, you’ll want at least 2-3 layers for a good mushroom bed. After you crumble the final layer of spawn on top, add one final layer of straw on top. I’d suggest using a garden hose sprayer to help get a nice even moisture level throughout your bed.
When you’re done, you can lay a plastic sheet (or tarp) on top to help hold moisture in as your mycelia begin to grow over the next few weeks. Cut a few little holes around the plastic sheeting, so your mycelia can still breathe a bit.
Keep an eye on your mushroom bed’s moistness level. If it gets a bit dry, add some more water and cover it back up. Look for patches of white mycelia: this is the beginning of your mushroom bed. Finding mycelia is always exciting (to me) and will let you know that you’re creating the ideal growing situation for your mushrooms.
It may take up to 3-4 weeks for you to begin seeing “pins” (tiny baby mushrooms.) Once you see mushroom pins, remove the plastic sheeting so they can breathe and continue to fruit. After you see pins, it won’t be much longer until you will be able to harvest some delicious oyster mushrooms for dinner!
Other Outdoor Growing Methods
Although growing outside is an easy option for the at-home mushroom cultivator, it has its downsides—specifically pests. Gnats, flies and slugs will find your mushroom patch to be a delicious smorgasbord of tasty treats. Be prepared for little nibbles or friends living on or in your mushrooms. I mentioned earlier a few ways to attempt to deal with such pests.
An alternative to growing a mushroom bed outside is to grow on straw logs, which is very similar to the next growing method in this article. The main difference is that these straw logs will be hung outside to fruit instead of in a controlled environment. I’ve heard that growing on straw logs outside can be a much more productive growing method and may be worth your time to try as well.
Growing in Polybags or Buckets
This method is a bit more involved, but still is easy enough that any mushroom growing enthusiast should give it a try! You will find that out of all the methods listed in this article, this method will give you the highest success rate and the best harvests.
Growing on wheat or oat straw seems to work pretty well for oysters.
Put your straw in a barrel and hit it with your weed whacker until it’s chopped up into about 1-3 inch pieces. Some folks like to soak the straw in water with a tiny amount of dish soap to help reduce bacteria and chances of contamination. Although, this step isn’t necessary.
Next, you’ll need to pasteurize your straw. For small batches you can add boiling water onto your straw periodically over a 1-2 hour time frame. Use a thermometer to make sure it stays above 149℉. For larger batches, you can use a large, food-grade metal barrel and a propane burner. Create a metal screen “basket” to hold your straw as it cooks. (Cook time and temp is the same as for smaller batches.)
While it’s cooking, prepare a clean table surface to spread out your straw on. Cleanliness is super important in this step! Wash the table surface thoroughly and disinfect your hands with alcohol (or wash them often). When your straw has cooked for the proper time, spread it out on the table and let it cool so you can begin making your straw logs (or filling your buckets).
After it has cooled enough to where you can handle it, mix in your spawn. (Remember to make sure your hands are clean!) For a good harvest, try using about 3 lbs of spawn for every 20 lbs of wet straw. Using any less than this will have a much higher chance of contamination.
Once the substrate and spawn are mixed thoroughly, you can begin putting it into poly bags (polyethylene bags) or into clean, food-grade 5-gallon buckets. I have even seen people grow in large Ziploc bags before! Drill 1/2-inch holes in buckets for mushrooms to grow out of before filling. If you’re using poly bags, wire or zip tie one end shut first. Keep at room temperature.
Push down as you fill your container with mixed substrate, preventing air pockets that might cause small mushrooms to grow where you don’t want them to. If you’re using poly bags, squeeze out any air and tie off the top. Cut little X-shaped holes in your new straw log to help your mushrooms breathe, and so they can find a good place to grow out of. For bucket growers, cover the top of your bucket with plastic wrap, cutting a few holes in it so that everyone underneath can still breathe.
After about 1-2 weeks, you will notice that your poly bag (or bucket) has begun colonization, creating a white mycelia web. If you see any colors other than white growing, your colony has been contaminated and it’s best to toss it in your compost and try again.
Soon, your substrate will be completely colonized and fruiting will begin! You can help fruiting by raising humidity, dropping temperature slightly, and adding a bit more indirect sunlight… but this isn’t necessary either. These are just steps you can take to get a better harvest.
Anywhere from 10-21 days after inoculation, you can expect to begin harvesting delicious mushrooms! They are ready when the caps begin to turn upwards.
Harvest, and Mushrooms’ Nutritional Value
Twist or cut off mushrooms in clusters, rather than picking individual mushrooms. You should be able to get 1-2 more flushes before your substrate is spent. Add the spent substrate to your compost heap when it stops producing. Let your harvested mushrooms dry a bit and store in your fridge in a brown paper bag. They’ll stay good for 1-2 weeks, but are best when eaten right away.
When dry, oysters contain between 15-35% protein, as well as good amounts of amino acids. They also have vitamins B, C, and niacin. Depending what substrate they’re grown in, their nutritional levels and vitamins can fluctuate.
Since there are a variety of different colored oysters available to grow:—pink, yellow, green, blue, and grey—you can easily add a rainbow of tasty color into your meals. Hopefully, you’ll find that one of these methods works well for you, so you can enjoy the experience of growing delicious fungi to share with your friends and family!