mushroom growing logo

How to grow White Button Mushrooms at Home

What is a White Button Mushroom?

A white button mushroom is a cultivated edible variety of the common mushroom commonly grown in homes and commercial kitchens. The cap of the mushroom can range from 1 to 4 inches (2.5 to 10 cm) depending on cultivation, with a pale brownish, almost beige coloration. Their stems are usually very short or sometimes even absent at the base of the cap. White button mushrooms are available fresh or canned year-round at grocery stores, where they are commonly found washed and prepackaged in shrink wrap.

Conditions Needed to Grow Button Mushrooms

While button mushroom cultivation is simple and easy, there are certain conditions that should be met for optimal results.

  • Amount of nutrients

Button mushrooms require a medium amount of nutrients in order to form. Composted materials such as leaves, straw, hay, or sawdust make great growing mediums--which leads us to the first necessary condition for growing them: humid conditions.

  • Humidity

Button mushrooms grow best in humid conditions and require a stable humidity of about 95% to develop. Therefore it is necessary to keep the growing medium moist at all times. This can be achieved by regularly misting the growing medium with water or wrapping the container in plastic wrap before sealing

  • Light

Button Mushrooms require a dark and relatively cool environment for optimal growth. Temperatures of about 15 °C (60 °F) allow for the best results. The darkness can be achieved by covering the growing containers with opaque plastic sheets, black construction paper, or simply by keeping them in a closed cupboard.

  • Soil Conditions

The most commonly used soil for button mushroom cultivation is rice straw, which is the byproduct of cultivating brown rice. It has a relatively low nutrient content and is very dry since it has been deprived of all moisture, making it an ideal medium for mycelial growth. It can be bought in large bags at any gardening store and is usually pretty cheap.

Growing White Button mushrooms at home

Using the Rice Straw Substrate

Materials required:

1. Sterilized pail (pail with holes drilled in the side allow for even drainage)

2. Rice Straw (sterilized by boiling or baking in an oven at 120°C for 1 hour)

3. Button Mushrooms (grown on sterilized, nutrient-rich substrates like ryegrass seed)

4. Water

5. Spore syringe (optional) or an alternative would be a spore print and some Vodka/Everclear

6. Disposable gloves and hand sanitiser. *Remember, Impetigo is very contagious! Protect your skin at all times!

7. Goggles to protect your eyes from any splashback


Step 1: Prepare the straw.

Involves boiling it for an hour to kill all living organisms and baking it in an oven at 120°C for another hour to completely dry it out to prevent any competitors such as bacteria or other fungi from growing alongside your mushrooms and take away vital nutrients needed for their growth.

Step 2: Prepare an environment with high humidity.

A humidifier or a container of water is good for this, but can also be done by putting wet towels at the bottom of your cooking container and covering it in plastic wrap before sealing it.

Step 3: Prepare the substrate.

This is done by mixing dry rice-straw (which has been sterilized) with water in a 1:1 ratio. This will be the growing medium for your mushrooms.

Step 4:

Add mushroom spores or mycelium to the rice straw substrate. If you are using spore prints, then add them at this point and mix well. If you are using mycelium, then follow the next step now.

Step 5: Prepare a clean environment with high humidity

This is done by filling a spray bottle with water and spraying your growing container with it to create small droplets on the plastic sheet. If you do not wish to use a spray bottle, then simply pour some salt and/or Vodka into a bowl of water and use it to mist your growing container.

Step 6: Spray down the rice straw substrate with water

Spray until it is moist (but not soaking wet). You should be able to touch the top of the substrate without making any imprints on it.

Step 7: Punch holes

Punch holes into the plastic sheet over your rice straw and cover it in tin foil before sealing it. You can now place your growing container in a dark and cold environment (an outdoor shed would be ideal for this).

Step 8: Monitoring growth

Wait patiently, checking on your substrate every so often to ensure that the moisture level is maintained at all times. If you find that the rice straw has dried out due to heat then simply spray it down again.

Step 9: Harvesting

The mushrooms are ready to be harvested when the cap starts to open up, exposing the gills underneath. Harvest them before this happens or else they will rot in storage due to the moist environment that they are in.

* Make sure that you wear disposable gloves when harvesting your mushrooms because their spores can irritate your skin and make it itchy and uncomfortable.

Using a growing kit

Materials required:

  • Growing kit
  • Wide mouth jar with a lid


Step 1: Open the box from your growing kit and assemble all of its components.

This should include a glass jar, a plastic bag, and a small packet that contains a mix of peat moss and vermiculite. Do not open this packet yet though.

Step 2: Cleaning

Clean the glass jar with clean water and dry thoroughly before opening the small packet containing peat moss and vermiculite, which should be placed in the bottom of the jar. When you mix them together they form a material similar to soil.

Step3: Open the bag containing the mushroom spores by cutting it open at one end. At this point, you should wear gloves because these are no easy tasks to clean off your fingers! Carefully reach inside and pull out the contents, which should be a small pile of brown powder with some larger dark clumps in it.

Step 4: Add 1 to 2 tablespoons of water into the glass jar, making sure that you do not add more than is necessary or your growth medium will become too wet. Then sprinkle the contents of the mushroom spores bag on top of the moistened growing medium.

Step 5: Screw lid onto glass jar, place in a dark area at 15 degrees Celsius, mist twice daily with water, and wait for the mushrooms to grow.

How to grow Button Mushrooms without a Kit

Materials required:

  • Sterilized substrate. The substrate is the material in which mushroom mycelium grows and produces mushrooms, similar to soil.
  • Wide mouth glass jars with lids that can be sealed airtight
  • Misting bottle
  • Clean cotton swabs, an old paintbrush
  • Clean gloves

Step 1:

Sterilization of the jars and substrate. Clean the glass jar and lid. Boil them in hot water for 10 minutes. Let them dry completely before proceeding to the next step.  Separately boil the potatoes and rice, then allow to cool.

Step 2:

Once the substrate is cooled, inoculate it with mushroom spores by adding about 1/4th teaspoon of powder to each jar. After this, remove any large clumps of the material so that it is more evenly mixed when you add water later on.

Step 3:

Next, add about half a cup of water into the glass jar, making sure that you do not add more than is necessary or your growth medium will become too wet. Then screw the lid onto the glass jar tightly and place it in a dark space at about 27 degrees Celsius. Mist the jar twice daily with water to keep humidity levels high. As soon as you see small white bumps start to appear on the surface, remove all other substrate material inside the bag and continue misting it in water each day.

Step 4:

Once the white bumps start to grow into mushrooms about an inch tall, it is time to harvest them. this takes about  3 weeks. Use cotton swabs to gently scrape them out of the jar and place them on a clean, dry surface. If you want to save spores from the mushrooms for future use, carefully cut off a small portion of the stem with a razor blade.

Alternatively, you can harvest by squeezing each one gently below the surface of the substrate while pulling up with a twisting motion. Place harvested mushrooms in a paper bag and store in a dark dry place until required.

Step 5:

After harvesting, remove all uncolonized substrate material and mist the bag in water to keep it moist until your next harvest. You can reuse this bag for up to four harvests over a period of two months by simply adding more sterilized substrate each time you use it.

Button Mushrooms Growing Tips:-

1) Button mushroom kits should be used within a month of purchase, so try not to waste any time!

2) If your humidity levels are too high, you can reduce them by opening the lid of the growing jar for an hour a day.

3) If your humidity levels are too low, you can increase them by placing a small bowl containing 1 cup of water in the jar and surrounding it with plastic wrap before sealing the lid back on.

4) When mushrooms start to grow remove all other uncolonized material inside the bag and then continue to soak it in water each day.

5) If any material inside the bag starts to grow before the mushrooms, remove it promptly - this is known as 'greening'. This can be identified by its grassy smell.

6) Never eat button mushrooms that have not fully grown! They are very poisonous at this stage and can make you very sick.

7) Be careful not to eat button mushrooms that have been grown in the same conditions as poisonous varieties such as death caps!

Common Pests and Diseases

  • Green Mold

If a thick layer of mycelium becomes green. Mushrooms will be brown and cracked or deformed as they mature. Green mold can be eliminated by following careful cleanliness protocols, and it is vital to fully sterilize the compost before utilizing it.

  • Verticillium Spot

Verticillium spot is a fungal disease that affects the growth of mushrooms. You can get it if your mushrooms have small spots or misshapen caps. Verticillium spot causes white, fuzzy growth to grow on your mushrooms and can even cause them to become hairy.

You may remove the fungus by using salt. Place a cup of salt near the bubbles to dry them out. There are some fungicidal options for the verticillium spot, but it might also destroy the mushrooms.

  • Dactylium Disease

Webbed, cottony growth on the casing's surface and mushrooms are characteristic of this illness. It might turn grey or pink, and the mushrooms will develop a mushy, watery rot.

It is important to maintain good hygiene in order to get rid of Dactylium infection. Make sure the casing and all equipment are kept clean and sanitized.


White button mushrooms are among the most common types of edible mushrooms found in grocery stores. The above steps will help you grow white button mushrooms at home.

Remember that patience is key when growing these fungi. If you have any other questions about this process please consult a professional for advice on how best to cultivate them under your conditions. With luck and adequate care, harvesting succulent white buttons from your own kitchen could be just around the corner!

Meet the Author

Matthew is the proud owner of He loves growing all kinds of gourmet edible and medicinal mushrooms from the comfort of home - and is slowly trying to document his successes (and many failures!) here on this site 🍄 He loves nothing more than going out foraging - and out of season he tries his best to grow mushrooms at home, time permitting of course!
  • Val Bennallick says:

    It's nice to see a site that JUST gives you info from someone who loves fungi and NOT someone who leads you in with "tips" only to find you are being encouraged to buy their sponsored products or you have ads that you are "invited" to click on every 3 seconds!!! I have a Facebook page that is not for profit, not for clicks.... just to help people enjoy the same things that you do and have success. Well done 🙂

    • Matthew says:

      Ah thanks very much Val - that's very kind of you to say! What's the Facebook page, I'm interested in having a look 😊
      To be honest I may look at a way of bringing in some kind of an income from the site in some shape or form - but I really really hate the idea of covering the site in ads, so am looking for something a bit more user friendly. Watch this space 👀


    This is a site that aims to educate people about growing their own edible mushrooms from the comfort of their homes. We grow all kinds of foods in the garden - so why not consider growing your own delicious mushrooms too? 

    We aim to not only educate but also to provide a platform that helps other mushroom growers to sell their produce.
    linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram