After having a photo essay showcasing some of the many accents and Kusamono I have created by cultivating mushrooms in accent pots and driftwood published in Bonsai Today, I received many requests to explain the process that I use to do so.
The following is a step by step tutorial explaining one way in which I accomplish this. I have chosen to show first the easiest way, which is also the way with the lowest success rate. I have found that I achieve a much higher success rate taking tissue cultures, but that is a much more tedious and difficult operation requiring sterilization or pasteurization. There is however, already an excellent article on that can be viewed at http://www.shroomery.org/. . . Mushroom-Cultivation. Unfortunately, most on-line information on cultivating mushrooms deals with the psychoactive type.
The world is full of mushrooms of many shapes, colors and sizes; sadly they are often overlooked by many and simply referred to as Toadstools by others. I see mushrooms as undiscovered treasures in the woods, forests, and lawns that surround us. Once you start looking for them, you’ll notice that they are everywhere, they grow in wood chips, in lawns, on straw, on fallen logs, on living trees, and virtually everywhere else imaginable. Many of us have noticed them in our bonsai pots, this is a good thing, as they are the fruiting bodies of the fungus that lives in the soil and helps or trees grow.
When choosing a mushroom to cultivate for use, size should be of priority. In the picture above are some cultivated Psathyrella gracilis which I chose because of their pleasing shape and rich color, as well as for their naturally small size of just over an inch. They were also selected because they naturally grow on wood chips, a very easily obtainable and affordable substrate.
Besides coming in almost every color of the rainbow, mushroom also come in many different shapes and textures. In the picture above the Coprinus atramentarius I cultivated in a piece of pine wood have remnants of a universal veil still clinging to the caps, giving them an almost shaggy texture. The texture is carried somewhat further with the moss planted on the surface of the substrate. Both seem to work remarkably well with the piece of pine wood collected in the woods. Besides its clean beauty, I selected this species for cultivation based on its size (2-3 inches) and on the fact that it likes disturbed soil and often grows on or near decaying wood.
For the tutorial below, I have selected a very large mushroom for example purposes which would be too large as an accent for all but a very large bonsai. When choosing a mushroom to cultivate one must not only consider the size, shape, color, and texture, but also the pot to cultivate it in. Mushrooms can not be transplanted successfully in my experience, the mycelium, which in the ground could extend for miles, is damaged too easily and the mushrooms will quickly start to pale and in the case of Inky Caps such as the Coprinus atramentarius above, melt within hours.
Mushrooms reproduce by spreading spores, some by dropping them from gills or pores located underneath the cap, some by melting into an inky mess, and others like puffballs release them into the air above. These spores are what we need to cultivate mushrooms.
Spores are too small to be seen with the naked eye, they can however be seen when there are enough of them. In the picture above I have removed the stems from two mushrooms and placed the caps gill side down on a plain white sheet of paper.
In the picture above I carefully removed the caps after about an hour and now we can see the brown spore print around the damp area of the paper. The brown spore print is made up of millions of spores.
A close up of the spore print. I know some people who use the paper as “seed” for cultivating mushrooms but I have found that cutting out the middleman works best for me. Our goal here is to introduce all of the spores directly onto the substrate surface.
For our purposes I will use a single mushroom to “seed” the substrate with pores. With smaller sized mushrooms, I might use as many as a dozen mushrooms.
The mushroom I have selected naturally grows in compacted soil and I have also found it growing in wood chips so I have prepared a mixture of rotted bark, clay based soil, and vermilite which was sterilized by baking in a clay pot on an open fire. I bake my substrate once mixed and then store it in open buckets with drainage holes all year long until time comes to use it.
I remove the stem close to the cap with a pair of sissors.
I then lay the cap onto the substrate which is just barely wet and cover with plastic wrap. By barely wet I mean that if I took a handful and squeezed it, no water would drip out, but it is still damp to the touch. If you can squeeze water out, it is too wet.
I leave the cap on the substrate for 24 hours and then remove it, carefully covering the pot back up with the plastic. After a week I remove the plastic and move the pot under the deck where it will stay until the following spring or fall, depending on the species. (Any dark cool place would work, a shed, a basement, a garage, etc) The time it should be brought out is dictated by when the “seed” mushroom was collected. If I collect in May, then I’ll bring out the pot one month earlier the following year, in other words, eleven months. Great care must be taken to assure that the substrate never dries out or becomes water logged.
I “seeded” eight pots with this species and only one bore fruit. After eleven months passed I brought this pot out from under the deck and moved it to a warm semi shady location where it fruited nicely within a few days, so quick in fact that I almost missed it completely.
It is impossible to control how many mushrooms will come up, I often need to prune a few out in order to make a visually pleasing display, be careful though, you can’t add them back in. You should also be careful not to touch the mushrooms as many will bruise with ease.
I often get multiple flushes of mushrooms, a new set coming up as the older set begins to die back or even after they have died completely. Each new flush is different in number, sizes, and location.
Although the success rate using this method is low (about 25%) those that do fruit are remarkable and since they are growing in the pot, they last sometimes for weeks and multiple flushes can extend the show period by months sometimes. I make up for the low success rate by “seeding” multiple pots, assuring that the species I want will be at hand.
Note: The photo essay as published in Bonsai Today can also be viewed at http://www.artofbonsai.org/feature_articles/mushroom.php