How to Grow Mushrooms Indoors

Mushrooms are not only tasty. They are also filled with healthy nutrients, like calcium and potassium, and vitamins, like D and B.

Some people not only enjoy eating mushrooms. They also like to collect them in the wild. But that is not for everyone. While some people are knowledgeable enough to collect mushrooms in the woods and eat them, many people are not. Eating the wrong mushroom can make you sick or even ... dead.

Therefore, buying them is the easier and safer choice. However, there is another one: You can grow mushrooms yourself inside your own home.

This undated image provided by North Spore shows a variety of cultivated mushrooms in a cardboard box in Portland, Maine. (North Spore via AP)

In a recent article for The Associated Press, plant expert Jessica Damiano explains there are two ways to do this. You can buy a set of materials from a garden store called a "grow kit" or you can put them together yourself.

Grow kits

Grow kits are a great way for beginners to try growing mushrooms. These grow kits include partly-grown mushroom starters, called "spawn." The spawn is set in soil and is contained in its own grow box. You put the spawn in water overnight. Then you return it to the box and open it to fresh air. Spray it with water two times a day.

Within two or three weeks, you will be eating mushrooms with more on the way. Damiano says it is a fun, easy activity. And people will likely ask you about it.

Putting them together yourself

If you are more serious about growing mushrooms and want a larger harvest, Damiano says it costs less to put the materials together yourself. It is easy, she says.

For starters, you will need a wooden, metal, or plastic box or container. It needs to be about 15 centimeters deep and large enough to hold your harvest.

You will also need a growing substance -- soil mixed with compost and other materials. The materials depend on the mushrooms. White button mushrooms grow better in a half-and-half mix of compost and well-rotted manure. Oyster mushrooms do well in oat or wheat straw. Shiitakes, another kind of mushroom, like sawdust.

Finally, you will need fungal spores: Think of them as seeds. You can purchase these online or at specialty stores.

Clean your hands well. Avoid bringing bacteria, mold, or non-mushroom fungi into the box. Fill the box with your growing substance (soil and materials) leaving about 25 millimeters at the top. Put the spores evenly over the soil substance and gently wet it. Spray it with water twice daily. Keep it wet but not too wet.

To grow quickly and effectively, the spore-topped soil material should be kept away from direct sunlight. It should be kept at or close to 21 degrees Celsius. If you cannot keep a room in your home at that temperature, set the box or tray on a heating pad set to 21 degrees but no higher (warmer temperatures can kill the spores). A soil thermometer can help make sure the soil does not get too warm.

Put a piece of cloth lightly over the top of the box to keep moisture in. But do not seal it tightly.

Soon, a white coating will form on the surface of the soil. That is mycelium, a network of fungal threads from which your mushrooms will grow.

When the soil is completely coated with mycelium, top it off with a bit more of the soil mixture. Remove any heating elements. And move the tray to a cooler spot – 12 to 15 degrees Celsius.

Mushrooms usually grow, or "fruit," within a week or two. They nearly double in size daily until they are finished growing. Depending on the kind of mushroom, they will be ready to harvest, with their tops fully open. That will be in roughly three to four weeks. Use a sharp, clean knife to cut them at soil level to avoid disrupting nearby growth.

I'm Anna Matteo.

Jessica Damiano reported this story for the Associated Press. Anna Matteo adapted it for VOA Learning English.

Words in This Story

spray – v. to scatter or apply lightly and in small amounts

well-rotted – v. to decay due to the action of fungi or bacteria to high degree

manure – n. bodily waste from birds and animals in stables and barnyards with or without litter

fungal – adj. of, relating to, or having the characteristics of fungi

spores – n. a primitive usually unicellular often environmentally resistant dormant or reproductive body produced by plants, fungi, and some microorganisms and capable of development into a new individual either directly or after fusion with another spore

mold – n. a superficial often woolly growth produced especially on damp or decaying organic matter or on living organisms by a fungus

pad – n. a thin flat mat or cushion

moisture – n. liquid diffused or condensed in relatively small quantity