The terms flush and break are names given to the repeated 3 to 6 day harvest periods during the cropping cycle. They are followed by a few days when no mushrooms are available to harvest. Once mature mushrooms are picked, an inhibitor to mushroom development is removed, and the next flush moves toward maturity. The regrowth repeats itself in a 7 to 10 day cycle, and harvesting can be repeated as long as mushrooms continue to mature, though the yield decreases with each picking cycle. Most mushroom farmers harvest for 21 to 35 days, but harvest can continue for as long as 150 days. Temperature, water management, and ventilation continue to be critical parameters throughout the growing period. At Mountain Meadow our harvest period is 21 days because of our integrated pest control program we eliminate or control phorid and sciarid flies.
One deciding factor related to the length of harvesting time is the necessity to maintain low levels of disease pathogens and insect pests so as to minimize the use of pesticides. Mushroom pests can cause total crop failure. These pathogens and insects are controlled by cultural practices coupled sometimes with the use of government approved pesticides. Mountain Meadow focuses its efforts on physically excluding these insects from the growing rooms. Shorter harvesting periods reduce the time for pests to become established and proliferate in the crop or growing rooms. After the last flush of mushrooms has been picked, the growing room is closed off and a clean up performed. The room is pasteurized again with steam at 150oF for 18 – 24 hours. This final step is designed to destroy any pests, which may be present in the crop or the growing room, thus minimizing the likelihood of infesting the next crop or other rooms. This also results in a used compost free of weeds and other pests that can be used by gardeners and landscapers.