How to Grow Mushrooms on an Outside Log

Obtain logs from a hardwood tree. The best choices of wood include maples, oaks, elms, beech, black gum and honey locust. The logs should be no larger than three feet long and six inches wide. Place the logs in a tub of fresh water and allow to become waterlogged.

Load a drill with a bit that's approximately 1½ inches long and 5/16 inch wide. Drill holes in the logs about five inches apart for a total of 20 to 30 holes in each log. Hammer a spawn plug of oyster mushrooms into each hole during the late spring or early fall. Use a punch to drive the spawn plug about a quarter inch below the log's surface.

Place cheese wax in a crock pot and melt it under very low heat. Draw the liquid wax into a turkey baster and seal the holes in the logs with wax. You can identify each log by marking a metal tag with any necessary information and attaching it to the log.

Place the logs in complete shade and stack them so that the holes aren't blocked by anything. Water the logs with a soaker hose as often as necessary to keep them moist.

Soak the logs thoroughly in about six months during the late spring or early fall to induce the spore plugs to produce fruit. The mushrooms should be fully mature in another six months. You'll get the best results when the temperature stays between 60 and 70 degrees Fahrenheit.