Portabella mushrooms are not as difficult to grow as one may think. They can be grown both inside and out successfully. The key to their production is to use the correct materials and to plant them when the temperature is right.
Outdoor Portabella Mushroom Production
This form of mushroom grows well in compost but before you begin the process you will need to build a raised bed that is 4 feet wide and at least 4 feet long with a depth of 8 inches. Once that is done, fill the bed with 5 to 6 inches of well-seasoned manure based compost. Cover with cardboard and then top with black plastic. Attach the plastic to the bed. This step will sterilize the soil through solar radiation. Keep the plastic on for at least 2 weeks.
While you are waiting for the soil to be sterilized, order your portabella spores.
After the 2 week period has passed, remove the plastic and cardboard. Sprinkle a 1 inch layer of portabella spores on top of the compost and gently mix in. Let the inoculated compost set for 2 weeks. Once this time period has passed, one should begin to see a white film appear over the soil. The presence of this white film is proof that your spores are growing.
Now, premoisten peat moss and apply to the compost making sure that you lay an even 1 inch layer. Top the peat moss layer with newspaper and mist with distilled water. Continue the misting twice a day for 10 days. After the 10 day period has passed, remove the newspaper and continue with the misting schedule for another 10 days.
Monitor soil moisture and adjust as needed. Harvesting can be done anytime and is up to personal preference.
When planting portabella mushrooms outside make sure to monitor the outdoor temperature. Portabella’s require daytime temperatures that do not exceed 70 degrees Fahrenheit and nighttime temperatures that do not dip below 50 degrees Fahrenheit.
Indoor Portabella Mushroom Production without a Kit
For some, growing portabella mushrooms indoors is better alternative. The temperature of the environment can be controlled, which allows the gardener to grow the mushrooms year-round.
To begin the process, one will need to set up a tray as the bed. This tray will need to be 8 inches deep and 6 to 8 feet long. Place 6 inches of seasoned manure based compost in the tray. Sprinkle with portabella mushroom spores, mix gently into the compost and then press down. Put the tray in the dark until you begin to see white growth. After this growth has been observed, lay down a layer of damp peat moss and top with a layer of newspaper. Mist as above for 2 weeks. Then remove newspaper and check for mushroom development. If you see little white heads forming then leave the newspaper off. If you do not, place the paper back and continue to mist daily for another week. After that week has passed check again for mushroom development.
After the paper has been removed continue to mist daily. You should be able to get several flushes of mushrooms from this initial process.