How to Grow White Button Mushrooms

Co-authored by Lauren Kurtz

Last Updated: December 25, 2020 Approved

Growing white button mushrooms is a great project for a beginning gardener because their spores grow quickly and easily. Since they can be grown indoors, you can plant them at any time of the year. To grow button mushrooms, all you need is the proper equipment and some patience!

Part 1

Part 1 of 3:

Setting Up Growing Trays

1
Consider buying a kit if it's your first time growing mushrooms. Mushroom kits normally have all of the materials that you need for planting and growing mushrooms, and are great for beginners. They usually contain manure, substrate, trays, and a spray bottle for watering the mushrooms.
- Growing kits tend to have specific directions that may differ from traditional mushroom growing methods. Be sure to read the package carefully and follow the directions.
- Some kits already contain the spores for growing a specific type of mushrooms, while others just contain growing trays and appropriate substrate.
2
Buy large trays for growing the mushrooms. Select trays that are about 14 by 16 inches (36 by 41 cm) and at least 6 inches (15 cm) deep. To start out, only plant in one tray, which will continue to produce mushrooms for 3-6 months.
- Trays can be made of plastic, metal, or wood, depending on what you have available.
- As you become a more experienced cultivator, you can grow multiple trays at once and have an almost constant supply of mushrooms!
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3
Make a mixture of equal parts compost and manure. Button mushrooms require a growing environment that contains a lot of nitrogen. Use your own compost and purchase manure, like horse or cow manure, at the store, or buy both if you don't have a compost pile.^{[1]
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- If you plan on growing a lot of mushrooms, you can make this mixture in a large bucket and cover it after you use some of it. Otherwise, only mix as much as you'll need to fill one tray.
- Your manure and compost mixture will produce a strong smell, so make it in a well-ventilated area.
4
Fill the trays with 6 in (15 cm) of the growing mix. Pour the mixture into the trays carefully, leaving at least 1 inch (2.5 cm) of space at the top of the tray. Make sure the soil is level and is spread evenly across the tray.^{[2]
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- White button mushrooms tend to spawn well in warm compost, so don't worry if the compost is still hot when you place it in the tray.

Part 2

Part 2 of 3:

Cultivating Mycelium

1
Purchase ready-made spores online or at a nursery. To easily grow mushrooms, purchase spores that have already been “inoculated” or mixed in with a substrate, like dirt, hay, or sawdust. Button mushrooms are very common and available through online retailers, and can even be found in local nurseries.^{[3]
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- Whenever possible, purchase spawn from an experienced mushroom cultivator. These spawn will be more likely to produce mushrooms.
2
Spread the spores on top of the compost and mist with water. Since the spawn is pre-treated, you can apply it directly on top of the compost mixture. Try to make an even layer across the substrate so the mushrooms will grow in all parts of the soil.^{[4]
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- Mushrooms like to grow in a damp environment, so even if the manure and compost are wet, spray the tray thoroughly with water.
3
Place the tray on a heating pad to raise the temperature to 70 °F (21 °C). Set the tray directly on top of a pre-heated pad that plugs into a wall and has a temperature control dial. Place a thermometer in the soil to monitor the temperature as it rises.^{[5]
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- Avoid heating the soil any higher than 70 °F (21 °C) because it can kill the spores before they grow.
4
Move the tray to a dark room, and spray with water 2 times per day. The mushrooms will grow best in a dark place, like a root cellar, basement, garage, or even a closet. Throughout the day, check the temperature and moisture of the soil to make sure it isn't too warm or dry. Spray the soil with water thoroughly 2 times per day.^{[6]
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- If the soil is frequently warm, try lowering the temperature of the heating pad and keep an eye on the thermometer.
5
Lower the heat to 50 °F (10 °C) once tiny, thread-like roots form. After 3-4 weeks, the top of the soil will be covered in tiny, white roots, called “mycelium.” When the soil is completely covered, lower the temperature to encourage growth of the first mushrooms.
- Some areas of the tray might form mycelium early, while others will take a full month. Be patient throughout the process, and wait until the colony is fully formed to lower the heat.

Part 3

Part 3 of 3:

Growing Mycelium into Mushrooms

1
Cover the mycelium with 1 in (2.5 cm) of potting soil. As the temperature falls, spread a layer of regular potting soil over the newly formed roots. This layer will protect the delicate mycelium and provide nutrients for the new mushrooms as they grow.^{[7]
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- You can find potting soil at most home improvement stores or garden centers.
2
Water the soil daily and cover the tray with a damp cloth. In order for mushrooms to grow, the environment has to be constantly moist. In addition to spraying the soil with water, drape a damp cloth over the tray to release water into the soil throughout the day.^{[8]
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- If you don't have a cloth to cover the tray, you can use a layer of damp newspaper spread across the top of the soil. When mushrooms begin to form, remove the newspaper.
- Make sure to keep the cloth damp, as well, by misting it, or just running it under water for a few seconds.
3
Wait 3-4 weeks for mushrooms to sprout from the soil. About a month after spreading the potting soil, the first mushrooms should sprout from the soil. Allow them to reach full maturity before harvesting them to eat.^{[9]
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- Once mushrooms begin to form, continue to mist the soil. A single tray of spores can produce mushrooms for 3-6 months after the first sprouts.
4
Harvest the mushrooms when the caps open. When mushrooms are mature, the cap will pop open. Use a sharp knife to slice through the stem, just below where the cap meets the stem. Some gardeners choose to twist off the caps to avoid cutting the stem.^{[10]
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- If you're not sure how to prepare your mushrooms, you can try sautéing them, making a cheesy mushroom pull apart bread, making mushroom gravy for chicken, or eating them raw!

Community Q&A

Question

I am growing white button mushrooms from a kit. Is it possible to save or move some spores to make more mushrooms? What is the best way to propagate these mushrooms to not keep buying new kits?

Community Answer

You can propagate the Mycelium on wet shredded cardboard in a container with holes at the bottom. Seed it with the area around each mushroom root and keep it moist and dark for 1-2 months until you see the white growth on the pieces of cardboard. Use the cardboard bits to start a new tray of mushrooms.
Question

How long does it take to grow white button mushrooms?

Drew Hawkins1

Community Answer

In order to grow mature white button mushrooms, you have to first cultivate mycelium, which will take about 3-4 weeks to start sprouting tiny mushrooms. Then, it'll take about another 1-2 weeks for the mushrooms to grow large enough for you to harvest them. Once the mycelium starts sprouting mushrooms, if the conditions are right, you can continue to harvest mushrooms for up to 6 months.
Question

Where do white button mushrooms grow?

Drew Hawkins1

Community Answer

White button mushrooms naturally grow in fertile and damp soil, which is why they were first cultivated in fields with horse manure. You can grow them at home by making a mixture of equal parts compost and manure and filling a tray with it. Then, add spores over the surface and wait for the mycelium to form, which is a network of filaments that the mushrooms sprout from. After a few weeks, you'll see tiny white button mushrooms growing.