How To Grow Oyster Mushrooms

How to Grow Oyster Mushrooms

There are varieties of oyster mushroom to choose from if you want to start growing your own. We will talk about the most commonly grown oyster mushroom, known as the common, winter, pearl or gray oyster mushroom.

Oyster mushroom (Pleurotus ostreatus) cultivation can either be a good business starter or a leisure for aspiring gardeners. For individuals who do not have a big spare space for farming, planting these edible mushrooms is not a problem. A small room within your home can suffice. Additionally, taking care of the fungi is relatively easy even for first-time growers.

Oyster mushrooms are fast growing with healthy culinary benefits as well. In the wild, these grow on logs, dead trees and on varied substrate sources. Refer to the enumerated steps below for a detailed guide on how to grow oyster mushrooms.

Prepare Cultivation Materials

  • Straw (growth medium)
  • Large pot for boiling
  • Plastic bags
  • Mushroom spawn (100g – 1kg)
  • Gloves and face mask
  • Water sprayer
  • Thermometer
  • Growth room/area
Image of Oyster Mushroom by Wendell Smith

Steps to Grow Oyster Mushroom

1. Obtain Oyster Mushroom Spawn

The option to buy ready-made spawn is cheaper than producing your own from scratch. You do not have to necessarily travel to find and buy mushroom spawn. There are online shops like Field & Forest Products and North Spore that offer different choices of oyster mushroom spawn for starters.

You can order from them and have the products delivered to your home or farm address. Prices start at $22 for retail up to $300 for bulk orders. Also, local commercial mushroom suppliers might be available near you, look for Fungi Perfecti, Mushroom Adventures, or Mushroom Central Supply, Inc. These local stores have online shops and websites as well.

The aforementioned shops do not only have mushroom spawns, they sell growing kits, planting accessories and planting media as well. Amazon and eBay also sell mushroom spawns.

2. Set-up the Growth Area

Oyster mushrooms grow best in dim areas and a humid environment with no contact with sunlight, although you will need natural light during the fruiting process. Cover windows temporarily and use a thermometer to make sure that your growing area is within the optimal temperature which is around 75-78 degrees Fahrenheit (23-25 degrees Celsius).

To save space, you can use shelves to put your inoculated straw bags into. Clean the area thoroughly before setting up to avoid contamination.

3. Prepare the Substrate & Inoculate Oyster Mushroom Spawn

Use personal protective equipment such as mask and gloves during this step to avoid contamination of cleaned substrate. In deciding which substrate to use, you have choices like straw, wood chippings, sawdust, card board and other agricultural byproducts. Many growers prefer straw and it is also the most widely used.

Buy amounts depending on how much room you have and yield you want to achieve. Use straw that are cut into small pieces ranging from 5-10 cm (2-4 inches) in size. Prepare the straw by immersing it into water and rinsing it thoroughly. Then, use a large pot to boil the straw.

In order to make sure your medium is sanitized, boil it for thirty minutes up to one hour. If you have the equipment, you can also autoclave your substrate for complete sterilization. Drain and spread the straw into a big, clean tray to let it cool down. Make sure it is wet enough (74% hydrated) before packing.

After cooling down, use the plastic bags to pack at least 3 inches of straw and then scatter spawn on top of it. Continue stacking layers like this until you come up with your preferred size. The photo below shows a large straw bag example.

inoculated straw log with pinning
Oyster Mushroom Straw Log Fruiting Image by Wendell Smith

Fill the whole bag and seal the top by tying. Poke holes every 10 cm around to give room for air. Arrange the inoculated straw bags in your growing area.

4. Incubation and Colonization

This step will take at least 10 days up to 3 weeks. The area where the bags incubate must be completely dark with strictly no exposure to light to prevent untimely fruiting.

 The whole bag must be covered almost completely in white before you start the next process. Prevent mold contamination by regularly checking for green or black mold growth. Examine if contaminant mold overpowers your mushroom colony, if this happens, and remove contaminated bags immediately.

5. Pinning or Fruiting

You will know you can already start the pinning process when small pinhead parts of the mushroom are already growing near the plastic bag’s holes. This is also called fruiting.

pinning oyster mushroom
Image of Pinning Oyster Mushrooms from Rooted Valley

Heighten the level of humidity in your growth area for this development. Keep the temperature ranging from 65-70 degrees Fahrenheit (18-21 degrees Celsius). Spray water around the straw bags, floor and not directly on the fruiting mushrooms to maintain this optimal condition. Leaving open water containers around the area can facilitate in achieving 95% – 100% level of humidity.

Expose your growing oyster mushrooms to indirect natural light for least 12 hours a day. In addition, make sure fresh air is getting in to your growing area. Excessive carbon dioxide (CO2) and little oxygen will lead to long and thin growing stems. Give them room for growth by cutting the plastic bag open and taking it off. In this phase, the medium must be able to maintain its shape. Continue maintenance until you can harvest your mushrooms.

6. Harvesting Your Oyster Mushroom

You can start harvesting your mushrooms depending on your size preference but it is better to harvest them before the oyster mushroom’s caps start to flatten and produce spores. Cut the mushrooms as close where they started to grow.

ready to harvest oyster mushrooms
Image of Ready to Harvest Pleurotus ostreatus by Ultimate Mushroom

Continue adding straw and maintaining moisture to produce more yield. Spray water around at least twice a day. After harvesting, just rehydrate the substrate. To facilitate continued growth of your oyster mushroom, maintain the optimal temperature, sunlight and humidity for fruiting. You can continue harvesting as long as fruiting continues. If growth stopped, this means all your substrate nutrients are already consumed. You can use the substrate remains as compost.


Growing oyster mushrooms is inexpensive. It does not require hard-to-find materials and most of the things you need can also be found inside your own home. Spawn and substrate are readily available on the market. If you do not do well at first, you can always try again.

Once you have learned the basic needs of your oyster mushroom, and you have succeeded in growing them, you can use your products not only for your own supply at home but also as a source of income. Start growing oyster mushrooms now!

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