How to Grow Button Mushrooms Indoors

Sterilize a glass jar with a lid with hot water and dishwashing detergent. Rinse well to remove residual soap. Use a sharp knife or pliers to punch five or six small holes in the top of the lid for air circulation.

Fill the jar three-fourths of the way with aged compost. Button mushrooms grow better on compost than on other substrates, but the compost must be around the middle of its maturation process, so that competitive fungi are removed but microbes that aid in mushroom growth remain.

Add button mushroom spore to the compost in the jar. The spore often comes in a powdery form or on dowel rods that you can bury in the compost. Make sure the spores are buried within the compost and not just sitting on top.

Store the jar in a dark area that maintains a temperature of 65 degrees Fahrenheit. A temperature variation of 2 to 3 degrees in either direction will be OK, but do not allow temperatures to fluctuate more than that.

Check the compost every two weeks to ensure that it is moist; add more compost or a little lukewarm water if necessary. Mushrooms should sprout within five to six months.