Since we like mushrooms in all forms, dried, fresh, and canned; and since mushrooms not only are nutritious but add texture to various dishes I’ve attempted in the past to grow fresh mushrooms from the commercial kits offered in garden catalogs. My experience has been mixed. When I started growing mushrooms back in the 1990’s I had much greater success in bringing mushrooms to table. However, over the past few years these kits have met with increasingly less success. I honestly believe that this is related to the producers of these kits accelerating production of the kits as the demand has increased; this compared to my earlier successful attempts when growing your own was not as popular.
I recently came across a small company that sells a convenient mushroom package requiring little care other than cutting the bag open and keeping it moist. These are sold to the WholeFoods chain of alleged organic and natural foods, (long time readers of CRS know my feelings on the reliability of commercial organic grocers). However, in speaking with the Produce Manager at my local WholeFoods it is no longer available for reasons unknown. This now left me with the dilemma of how to home-grow my own mushrooms without resorting to the expense of going to specialty spore producing companies.
Since necessity is the mother of invention, I’ve decided to proceed with a bold pioneering project of growing my own from scratch, so to speak, by buying fresh grocery store mushrooms meant for eating and attempting to cultivate my own mushroom spores from the store produce. After studying mycology and viewing a few YouTube videos I think this innovative approach is likely to be successful …clearly as successful as the commercial attempts I’ve made of late and with less cost.
Assembling the Materials
First, there is manure, traditionally this is horse manure and is what is provided in the commercial kits. For my first attempt I will use commercial, sterilized, and composted cow manure. Eventually, I will use horse manure and my own rabbit manure that is abundant here at Hunny-Bunny Farm. To this I will add a small amount of nitrogen from my fresh chicken manure and pulverized gypsum from some scraps of wallboard. With the addition of water I will compost this for a period of 21 days. This will allow the native bacteria and organism to breakdown the nutrients to a usable media.
Next, I will take the growing media as outlined above and sterilize it in a low-heat oven for several hours, i.e. 2 to 3 should be enough, using a disposable lasagna pan. After it has cooled to below 75⁰F it will be transferred to a small plastic shoebox. Shoebox size will be adequate for the moment since initially it will be only be Mrs. McC and I who will be eating them.
The third step which, will be done simultaneously with the first step of 21 days, will be to buy some fresh organic button mushrooms from the health food store and use these as my spore producing foundation stock. This is done by carefully popping out the remaining stem from the head to expose the inner cap where the spores are produced. To harvest the spores it should only be necessary to lay the heads face down on some colored cardboard. (Since spores are generally white, black, or brown, the colored cardboard will make the spores stand out.)
The fourth step will be to inoculate the now sterile medium with the harvested spores. This is done by cutting the cardboard containing the newly acquired spores into tiny bits and gently stirring them into the very top layer of the media.
Next, peat moss, with the addition of a very little lime (as a pH adjustment tilled in). This will be placed on top of the inoculated medium to a depth of no more than ¾ of an inch. This new blended media will be watered with a cup of tepid water and then thoroughly misted to cover the surface.
Finally, the shoebox will be covered to prevent moisture loss.
After initial setup the box will be kept closed for about two weeks. At this point the entire surface will have a fuzzy whitish-gray coating, looking very much like mold. This is the mycelium, that is, the vegetative part of a fungus, (after all that is what a mushroom really is …fungus), consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro. At this time check the moisture level in the box, it should not be saturated or completely dry. If not saturated, mist heavily to retain an overall surface moisture and humidity. The cover may be left open or partially open depending on the surrounding humidity levels and the moisture level of the medium. Sometimes newspaper lightly placed over the top will be all that is needed to retain the needed levels.
The mushroom box must now be moved to a dark and cool place of 55⁰F to 65⁰F. Over the next week to two you will observe white “pin heads” . This is a critical time as too much water or too little moisture can ruin your entire efforts. The best way to add moisture is via a mister, unless the medium is becoming too dry. Now just wait for your mushrooms to grow.
There are three stages at which to harvest the mushrooms. The quantities of mushrooms harvested are dependent on the nutrients gleaned from the media, as well as, moisture content. The three stages of harvest are: button – small unopened mushrooms; these are very tender and have a mild taste. Fancies – are slightly larger and have a more flavorful taste. At this stage the veil, or the membrane that covers the underside of the head is intact and the “gills” are not yet exposed. Flats – These are the largest and have the most flavor and nutrient content. At this stage, the head flattens out, the veil breaks open, and the spore producing gills are exposed on the underside of the mushroom caps.
When harvesting mushrooms hold the heads and lightly twist in one direction. This will leave a portion of the stem intact. Remove the remaining stem from the medium as they will contribute nothing to production of further mushrooms. If the mushroom heads are clumped, remove the center head as above and then cut the remaining heads from their stems.
Your mushrooms may continue to produce depending on the variety and the amount of nutrient and water in the compost. Generally this can be between 3 to 5 weeks, though some varieties can go on to produce for 12 weeks. If you wish continuous harvests start another box every 2 to 3 weeks this will prolong your production indefinitely limited only by your consumption habits.
Mushrooms are a practical gardening produce that will really be of benefit with relatively little energy or space expended. Give it a try it will grow on you!
Richard of Danbury, D.S.G.