How To Grow Mushrooms At Home Without Spores: Step-by-Step Guide, Care Tips, Precautions, and FAQs

Grow Mushrooms At Home Without Spores


Mushroom is an umami flavored fungi relished by many around the world. It is consumed for a myriad of health benefits as a stand-alone snack or added to dishes to enhance their flavor. Mushrooms are almost fat-free, low on calories, and contain essential nutrients such as potassium, phosphorus, B vitamins, antioxidants, etc. Many nature enthusiasts take up the hobby of cultivating Mushrooms are almost fat-free, low on calories, and contain essential nutrients such as potassium, phosphorus, B vitamins, antioxidants, etc. Many nature enthusiasts take up the hobby of cultivating mushrooms at home since growing any fruit or vegetable (and in this case, a fungus) gives you a sense of accomplishment and is also a great way to connect with nature. While you can easily find pre-colonized mushroom growing kits online, many harvesters are now learning how to grow mushrooms at home without spores.


Mushroom spores are tiny reproductive cells that replicate the mother mushroom’s blueprint and grow into new mushrooms. However, seasoned mushroom harvesters avoid using the spores for cultivation since the spores do not produce mushrooms with the same genetic strain.


Therefore, you may not necessarily get the mushroom you desire.


To maintain an identical genetic strain, cultivators are now using the tissue culture technique for growing mushrooms without a kit. Whether you wish to harvest mushrooms as a hobby or grow them commercially, searching “how to grow mushrooms at home without spores?” can help you learn how to grow mushrooms.


Table of Content


What Types Of Mushrooms Can You Grow Indoors?

Mushrooms grow best in a dark, cool, and humid environment, and therefore growing mushrooms indoors is easier since you can control the growing environment. Spots such as the basement or area under the sink are ideal for cultivating your stash of mushrooms. There are a variety of mushrooms that you can experiment with while learning how to grow them at home. Some of the popular varieties that you can try for growing mushrooms without a kit are Oyster mushrooms, Shitake, Button/Crimini/Portobello mushrooms, and Enoki mushrooms.


Other varieties that you can experiment with to learn how to grow mushrooms at home without spore include Blue Oyster, Lion’s Mane, and King Trumpet. However, if you are a beginner, you should go for shitake or button mushrooms.


How to Grow Mushrooms at Home Without Spores: Step-By-Step Guide

Growing mushrooms without a kit is done using the tissue culture process. Most varieties of mushrooms grow well in a temperature range of 55 to 60°F and require a dark and humid environment. In this tutorial, we will teach you step-by-step how to grow mushrooms at home without spores. If you have been searching for “how to grow mushrooms without spawn” we will teach you how to produce the mycelium using the mushroom strain and agar in a petri dish. The resulting mycelium can be used to create spawn on your own.


Step 1: Sterilization

The first step begins with the identification of the right spot indoors for cultivating your mushroom. Any room that is dark, cool, and closed from all sides will work well as your harvesting station. You need to sterilize the room and all the tools that you will be using to grow your mushrooms. You can use an air filter to purify the air in the room. For the tools using 70%, isopropyl alcohol will work well for killing any bacteria.


Step 2: Mycelium Production

When learning “how to grow shrooms without spores?” the next step is to grow the mushroom tissue culture called the mycelium. For this, you will require an agar plate which is a sterilized petri dish with agar as a growing medium. The agar will facilitate the fungi culture in the right environment and temperature. All you need to do is take a tiny piece of mushroom that you wish to grow and place it on the agar plate.


Keep the agar plate in a dark room or a cabinet for around two weeks. Make sure to keep it a little moist and maintain a temperature of around 21°C (70 F) for the mushroom tissue culture to grow and fill the entire agar plate. This mycelium will be used to grow your mushroom harvest.


Step 3: Prepare the Spawn

The next step is to create a spawning substrate, which is an organic medium for the mycelium to grow and increase in size. While different mushrooms grow in different substrates, the most commonly used spawn substrate is barley. Follow these steps to create a spawn.

  • Soak a cup or two of barley in water overnight. Sterilize the barley in a pressure cooker.
  • Take a mason jar and fill ¾ of the jar with this barley. Create multiple jars to get a good amount of spawn.
  • Cut the agar containing mycelium into one square inch pieces and drop a few pieces in each jar.
  • Secure the jar’s lid and make multiple holes in the lid to allow the mycelium to breathe. Place a medical sponge under each lid to prevent any contamination by bacteria.
  • Put these jars in a dark area and allow the mycelium to grow. The room temperature in the area should be between 21 to 30°C.
  • Once the mycelium overtakes the entire jar, it is time to transfer it to the bulk substrate, where it will grow into mushrooms.


Step 4: Select the Right Substrate

When learning how to grow mushrooms without spawn, it is important that you select the right substrate for growing mushrooms. Button mushrooms respond well to compost, while the shitake and oyster mushrooms grow best on sawdust, woodchips, or straw. Choosing a substrate different than the one used for spawn yields better results since a new material provides extra nutrients for mushroom growth. Once you have procured the substrate, you will also need to pasteurize or sterilize it before introducing the spawn.


Step 5: Prepare the Substrate for the Harvest

Preparation of the substrate requires sterilizing the organic material before the spawn is introduced to the bulk material. If using compost, select the one that is full of white actinomycetes bacteria. The compost can be sterilized by heating it up to a recommended temperature to kill the harmful bacteria while keeping the beneficial microbes intact.


Once sterilized, calcium sulfate is added to the compost to ready it for harvesting. If you are using material like sawdust or wood chips, all you need to do is steep them in hot water to remove any harmful bacteria.


Step 6: Add Spawn to the Substrate

The final step is to add the grown mycelium or the spawn to the bulk substrate. The proportion of barley spawn and the straw substrate should be 5% barley and 95% straw. Put the mix in bigger bags and place them in a dark room. At all times, the temperature of 15°C to 21°C (60°F to 70°F) should be maintained along with 90 to 100% humidity and a low air exchange rate. It will take around 7 to 14 days for the mycelium to overtake the entire bag, provided that the right growth conditions are maintained.


Growth Stages Post Adding Spawn to the Substrate

Pinhead Formation

When the mycelium overtakes the large bags, it is time to induce pin heading by making holes in the bag, dropping the temperature to 10°C to 18°C, and increasing the air exchange rate and humidity. At this stage, indirect light is also introduced to allow the mycelium to form tiny knots that will grow into pins and later into full-grown mushrooms. Depending on the mushroom type, it should take 3 to 10 days for the mycelium to start pin heading.



The last stage is to allow the pinheads to develop into full-grown mushrooms. At this stage, you will have to increase the room temperature between 15°C to 30°C. The other factors will remain more or less the same. Allow the pins to grow for 3 to 8 days in this environment to get your first mushroom harvest.


When learning “how to grow mushrooms without spawn?” it can around 14 to 32 days for the mushroom to mature, starting from the day the spawn is introduced into the bulk substrate.


Care Tips and Precautionary Measures

In the process of learning how to grow shrooms without spores, you will have to keep the following points in mind.

  • Always wash your hands and legs with soap and water before entering the harvesting room.
  • Humidity is a key factor for the proper growth of mushrooms. Therefore, you must sprinkle water over the mushrooms from time to time to maintain optimum moisture content.
  • The harvesting room should be well insulated to keep the temperatures steady. Concrete walls and tiles work well to keep the area insulated. Also, fumigate the room before bringing the mycelium into the room.
  • Do not clean the floor of the harvest room with a broom.
  • Keep a check on the substrate for any sign of contamination. Remove such bags immediately to prevent contaminating other bags if you are cultivating in bulk.
  • Do not let too many people enter the room as it can disrupt the growing environment.
  • Avoid plucking the mushrooms with fingers as it can damage the fungi developing beneath the soil. Instead, use a sharp knife to cut the mushroom stalk from the base.


Merits and Demerits of Growing Mushrooms at Home


  • The biggest advantage of growing mushrooms without spores is that you get mushrooms that are genetically identical to the strain used for propagation.
  • The mushrooms produced are superior to store-bought ones.
  • Learning how to grow mushrooms on your own is fun and educational.
  • You become self-sufficient in producing mushrooms that you generally like to eat at restaurants.
  • You save money in the long run by growing expensive varieties at home.



  • It can be difficult to regulate the temperature and other factors for the proper growth of mycelium and other growth stages.
  • There is a high risk of contamination if proper sterilization is not carried out.
  • Growing mushrooms indoors can pose a risk to health since the humid environment becomes a breeding ground for mold and bacteria.
  • You can only grow a limited supply indoors.
  • Not using a kit and doing everything from scratch can be a cumbersome and costly process.


Frequently Asked Questions


1. How can I grow mushrooms without a kit?

The best way to grow mushrooms without a kit is through the tissue culture technique that uses the mycelium to produce genetically identical mushrooms.


2. Can I grow button mushrooms at home?

Yes, you can grow different varieties of mushrooms at home as long as you give them the right temperature and humidity for growth.


3. Do mushrooms need sunlight?

Mushrooms do not require sunlight since they don’t produce chlorophyll. However, they do require indirect sunlight or any dim light during their fruiting stage.


4. How many days do mushrooms require to grow?

Most of the mushrooms are harvested between 30 to 40 days.


5. Can you get spores from store-bought mushrooms?

Yes, you can derive spores from store-bought mushrooms. To do so:

  • Cut off the stem of the mushroom
  • Place the mushroom cap over a wax paper with the gill side facing downwards.
  • Let it sit for 24 hours, and the gills should release the spores on the paper.



The joy of harvesting your own crop is unparalleled. Therefore, learning how to grow mushrooms at home without spores can be a great experience. If you are up for the task, start with easy varieties such as oyster or button mushrooms as they are more tolerant to temperature fluctuations.


While you can get pre-colonized mushroom growing kits in the market, growing them on your own will give you more confidence as a gardener. Plus, you will also save money by growing mushrooms without a kit. One last piece of advice that we want to give to all home growers is not to lose hope. You may not get the desired result in the first attempt, but keep trying until you reach perfection.