You can grow your own edible mushrooms in a portable 5-gallon bucket. Oyster mushrooms (Pleurotus spp.) are the best choice for bucket growing, because they are less sensitive to growing conditions and less picky about growing media than other varieties of mushrooms. You can grow the mushrooms indoors or outdoors, as long as the mushrooms have the necessary humidity levels and growing temperature.
Drill about 10 holes, spaced approximately 6 inches apart, staggered around the center section -- the space that reaches from about 3 inches above the bottom of the bucket to about 3 inches below the top of the bucket -- of a 5-gallon plastic bucket. The mushrooms will grow out of these holes. Use a 1/2-inch drill bit. Dump the plastic shavings out of the bucket after all the holes are drilled.
Fill the bucket about half full with moistened growing media. You can use coffee grounds, sawdust, straw or a mixture of the items to form the media.
Open the bag of mushroom spawn. The bag is usually about the size of a loaf of bread with the spawn packed in straw or sawdust. Break off some of the spawn and mix it in with the media in the bucket. Continue adding media and mixing in spawn until you have used all the spawn and the mixture is about 1-inch from the top of the bucket.
Cover the entire bucket loosely with a clear plastic bag. Cut 12 X-shaped holes around the top and sides of the bag to allow some air to get in. When you see fuzz start to appear, indicating the spawn is colonizing the media, remove the bag and cover the bucket with a lid or just leave the plastic bag cover over the bucket.
Place the bucket in a humid environment at a temperature around 70 degrees Fahrenheit. Create humidity by misting the bucket daily or by setting the bucket in a tub that contains about 1 inch of water. If the bucket is covered with a bag, mist under the bag. Do not remove the lid from the bucket if you are using a lid. You are not trying to wet the growing media, you are just trying to raise the humidity around the bucket.
Increase misting to three times a day when you see mushrooms start to appear in the bucket holes. This takes approximately three to four weeks. As the mushrooms appear, cut an "X" in the plastic bag over each hole that contains mushrooms if you covered the bucket with a bag rather than using a lid. This gives the mushrooms room to grow. Mist the mushrooms that emerge from the holes so they do not dry out. Wet the mushrooms enough that they are shiny, but not dripping or slimy.
Break off the mushrooms when they get to the size you want. Mushrooms will continue to grow until the spawn is exhausted. If you do not see any new mushrooms for three weeks, the bucket is done producing.
Empty the spent mushroom spawn and media and clean out the bucket to reuse it with a new batch of spawn.