Harvesting begins on each crop approximately 65 days from the beginning of the composting process. The first mushrooms are ready to pick approximately 20 to 26 days after casing . Once the first
mushroom is picked, many more mushrooms mature and are picked within three or four days. This production peak is referred to as a “flush”. A new flush occurs every seven days. Each week then produces a new flush. Generally the first, second, and third flushes deplete the usable nutrients and water. By the end of the third flush, it becomes economically inefficient to continue to harvest the crop. Harvesting is the most labor intense, costly and most difficult process to control in a mushroom
production facility. The mushrooms are harvested, one at a time, selected for maturity, sized and graded in the production room.
 A mushroom growing room in the process of being harvested
 A worker picking on the top tray
 The room is usually completely dark (bottom), hence the flashlight. The light in the picture (top) is from a flash