How to Grow Button Mushrooms at Home

Agaricus bisporus or better known as a kind of edible mushroom is native to Europe and North America. Basically, they come in two colors: white and brown. When mature, they are known by the name portobello mushrooms or portobello for short. When immature and white, they are known as button mushrooms, white mushrooms, table mushroom, or champignon mushrooms – Source . Immature and brown, agaricus bisporus is known as Swiss brown mushrooms, Italian brown, cremini mushrooms, baby bella or chestnut mushrooms.

How to Grow Button Mushrooms at Home

Button mushrooms are our focus in this writing. This type is considered the most consumed mushroom in the United States, about 90% of total mushroom intake, according to the United States Department of Agriculture. Regular intake of button mushrooms is believed to reduce the risk of heart diseases, strengthen immune systems, protect your body from cancer cells and supply your body with a variety of vitamins C, D, B and minerals such as selenium, iron, magnesium, phosphorous,  potassium and zinc.

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As a common ingredient in soups or salads, you can easily look for button mushrooms from grocery stores as they are cultivated all year round. However, many are tempted to try growing them at home and in fact, it is not so difficult to master button mushroom growing techniques. Follow guides in this writing and you can execute mushroom growing plan yourself at home.

Growing button mushrooms tips

The quickest and easiest way to have button mushrooms grown by you is buying a prepared kit and follow attached instructions until the first buttons are ready for harvest. The kit already contains manure compost, inoculated spawn and casing. All you have to do is simply keeping it moist by watering in cool, dark place. Such kits may produce 3 to 4 crops every 10 to 14 days. However, for those who want to start growing button mushrooms from the beginning, detailed instructions below will be valuable to help you experience growing process.

Growing environment

Button mushroom does not need sunlight to grow, so it is perfect to grow them indoors or window sides where plant shade has fully covered most sun exposure. They can be grown all year round, but winter is the most suitable. The space for growing button mushrooms must be clean and hygiene as well to keep off fungi or harmful insects from attacking mushrooms.

Required materials

You will need to prepare several things for button mushroom growing as follows:

  • Compost manure: the food source for button mushroom, best to have the compost made out of horse or cow manure.
  • White button mushroom spawn: it is like the seed for sowing plants but mushrooms do not grow from seeds but spawn. You may shop for it from gardening stores or order online.
  • Boxes: those are to contain the substrate for mushroom growing. The boxes should be 6 inches deep at least.
  • Casing soil: you will need it add on substrate surface to promote mushroom fruiting
  • Garbage bag and newspaper: this is used to cover boxes surface to encourage mushroom growing.
  • A cool, dark, clean space where the temperature is maintained at 18◦C to 25◦C

Now you can head up button mushrooms growing process.

Compost preparation

Mushrooms grow from the substrate, but it should be the substrate that has decomposed rather than a fresh one. The best substrate should be horse or cow manure mixed with straw; however, in case the supply of this ideal compost is scarce, there is some way to create artificial compost from straw, ammonium sulphate, manure, urea, super phosphate, calcium carbonate.

Whether you prepare the compost with horse manure or other chemical materials, the straw should be wet thoroughly before mixing with the components. Making the straw wet by soaking it in water for 2 to 3 days, but be sure to keep it damp, not dripping wet. For horse manure, the formula would be 50% straw mixed with 50% manure and a little of gypsum.

For artificial compost, one formula for the proportion of materials could be wheat straw – 40Kg, ammonium sulphate 1.2kg, manure 6.8kg, urea 0.7 kg, super phosphate 1.2kg, calcium carbonate (chalk) 1.2kg. Blend the materials all together.

Growing button mushrooms tips

It is advisable to shelter the compost in an enclosed area, and cover it with polythene or tarpaulin to prevent the materials from drying away. Aerate to allow oxygen penetration and loosen the compost as it starts to sink. You will notice heat going up from the compost. This is evitable in decomposing process, and it helps to pasteurize the compost as well.  Let the compost cool up to be used and you can move to next step of pasteurization.

Compost pasteurization

Pasteurization is the process of reducing microscopic competitors in the mushroom substrate, allowing mycelium to flourish in a favorable environment and ultimately produce mushrooms. While sterilizing kills all living organisms, pasteurizing still keeps beneficial organism alive to assist inoculation later. For large amount of compost, you can let the composting process to generate heat at 60◦C to 70◦C and self- pasteurization. For small amount of compost, the heating up may not reach optimal temperature to kill off harmful organism. You can pasteurize the compost yourself by steaming. A large pressure cooker could be employed to process this. Fill it with water and heat up the cooker till the boiling point of the water. The compost could be put in the inner tray and the steam rising up from boiling water will help to pasteurize the compost. That steaming could be done in 30 minutes or more. Make sure the water does not reach the compost or boil away. You may have an oil drum (205 liter) to pasteurize larger amount of compost. Once the pasteurization is done, let the compost cool down to 20◦C to 25◦C for spawning as the substrate at more than 30◦C may get spawn killed off.


The pasteurized compost now can be filled in growing containers. They can make from plastic biscuit tins, polystyrene packaging boxes, polythene bags, cardboard or wooden boxes, but the ideal size should be  45cm x 45cm in length and width and 25cm deep. Clean the boxes well beforehand with soap and water and make sure cleaning detergent has been blasted off the boxes. The compost should be still damp enough. You can check it up by squeezing the compost in your hand and if the shape remains unchanged and a little water can still be squeezed off from the compost, it may be ideal to start spawning.

Fill the compost up to 15cm to 20cm the rim of the boxes, the left over space could be used to add up casing later. Spread the spawn over the surface of the substrate, and mix it thoroughly. 60g of spawn could be used for 4kg of compost. In order to encourage colonization, you should cover the boxes with polythene to create a high CO2 environment. Place those boxes in a dark place at the room temperature of 20 to 26◦C, not above 30◦C. The spawn run may take 11 to 21 days at optimal conditions and you will notice thread-like growths and cobwebs will cover the compost surface.


As long as the substrate has been fully colonized by white spawn, it is time to add some peat moss or casing soil to promote fruiting. Casing materials should be well prepared and free of stones. Harmful tiny insects or fungi should be greatly removed by spraying formalin into the soil and covering with polythene sheets for about 2 days. Add a layer of 2 inches or 5cm casing soil to the boxes. Make sure the substrate is still moist by watering if necessary. Then you should cover the whole things by wrapping bag or wet. You may notice very first mushrooms within a month later.

Button Mushroom

Pest or diseases controlling

Mushrooms of all types are generally vulnerable to fungi and any tiny insect attack. The best measure to avoid this is keeping the growing space clean and hygiene. Shelter the growing space by sheeting, proof nets or doors to keep flies, beetles or springtails away. However, air ventilation must be maintained as well. The ideal temperature is 16 to 24◦C and bed moisture should be somewhere 60% to 65%. Water is necessary to keep the substrate moist but don’t be tempted to over wet the whole stuffs constantly, which may result in fungi invasion. Pasteurization of growing materials is critically important so make sure you do it well from the beginning. As you notice any defected or damaged mushrooms, remove them to stop diseases from spreading further.


After all hard working days, you must feel great to enjoy picking up fruiting button mushrooms.   Simply twist the button and you can remove it from the bed. Each growing time may generate 4 to 6 flushes of mushrooms, and you can harvest them every 7 to 10 days. However, the latter flush may not be productive as the former ones. As long as no more mushrooms sprout from the substrate, you can use the compost as a precious soil conditioner.

To sum up

Going through integral steps in growing button mushrooms, you see it is absolutely possible to carry out the growing plan at home, right? As mentioned earlier, if you want to avoid all sweaty stages in preparing, pasteurizing, spawning, and casing for button mushrooms, simply buy a packed kit, water it and wait to harvest the result. However, it is worth a try to grow all from the beginning and you will be delighted to realize how tasty the fresh button mushrooms grown by yourselves.

Author Bio

Richard Clayton

I’m an owner of a gardening blog. I love gardening and lawn care. I can spend all of my free time taking care of my garden and discuss about gardening experiences with my friends, who have the same hobby as me. My website (My Greenery Life)  is a playground of us, where we can discuss everything about lawn care, DIY gardening and critter control topics.

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