Ouotdoor Mushroom Cultivation Directions
ABOUT THE USE OF PLUG SPAWN
What is Plug Spawn?
Plug spawn consists of small pegs of wood that are colonized by mushroom
mycelium. It is a convenient way to inoculate a log with a mushroom.
The basic idea is to drill holes in a log and put the pegs in the holes.
The mycelium then grows out from the pegs and into the log.
Log size
Logs used for cultivation are usually 4 to 6 inches (10 to 15 cm) in
diameter, but smaller or larger sizes can be used. Smaller logs tend
to have a shorter life span - they begin to produce mushrooms sooner,
and become exhausted sooner. Small logs also dry out more quickly, so
they require more frequent attention. For reishi and maitake, larger
logs tend to produce larger individual fruiting bodies, although for
oyster mushrooms this isn't usually the case. Of course, larger logs
are more difficult to handle and move, something to consider if you
plan to submerge logs to induce fruiting, a common practice in shiitake
log cultivation.
Log species
It is critical to use the right tree species for a given mushroom species.
The oyster mushroom is a generalist, and will do well on just about
any species of hardwood (broadleaf tree). Maitake grows best on oaks
stumps and Shiitake grows best on oak logs. Maitake and Shiitake can
also grow on other non-aromatic deciduous trees such as maple or beech,
but we don't recommend inoculating these species on anything other than
oak without ensuring the strain you are using does well on the alternate tree species. American Reishi tends to grow on hemlock. We use Eastern Hemlock, and we expect that our strains would also grow well on Western Hemlock, although we haven't confirmed this yet. While not as common, we have also noticed American Reishi naturally growing on Maple trees in Vermont.
The most important rule of any mushroom cultivation project is to start small and gain your own personal experience with the strains of mushrooms you are working with which can thrive on locally abundant (and affordable) substrates.
Timing
Ideally, logs should be cut while the tree is dormant - after the leaves
fall and before the buds break. This increases the nutrients available
for the mushroom, and also helps the bark adhere to the wood. Intact
bark is important for preventing contamination and retaining moisture.
Many mushroom growers also have success with logs cut during the growing
season, this is simply not as optimal as winter-cut logs.
Logs should ideally sit for a week or two between cutting and inoculation.
Living wood defends itself against fungi, and this time period allows
the tree's "immune system" to break down.
On the other hand, logs shouldn't sit any longer than about 3 months
before inoculating, because other fungi will begin to colonize the wood.
The exact amount of time before competitors are able to become established
depends on a number of factors, including airborne spore load, type of ground and degree of contact with it, log moisture content and tree species.
Other points
Logs intended for mushroom cultivation should be treated gently. If
the log is dinged up and the bark is damaged, the wood will be exposed
to contaminants - other fungi that will compete with the one you are
trying to grow. If the log is dragged through the dirt, contamination
risk will also increase. Logs cut in winter and skidded across the snow
come out cleaner and less damaged than those being skidded across dirt.
Stumps vs. Logs
All of our mushrooms will grow well on tree stumps, but maitake and
reishi prefer stumps. This is not to say they will only grow on stumps
- but they will fruit better on a log that is partially buried - a "simulated
stump". This is probably related to the higher and more constant
moisture levels that come with being in contact with soil. But remember
that contact with the soil is also a vector for contaminants. So our
recommendation for these species is to keep the logs above ground, and
properly watered, while they are being colonized by your mushroom, and
then to bury the bottom of the log 6 to 18 inches deep (the longer the
log the deeper it must be buried to prevent tipping over).
Inoculating
If the weather has been hot and dry, and the logs have been drying out,
water them or soak them before inoculating.
Inoculation holes should be 5/16 inches (79 mm) wide and about 1.25
inches (3 cm) deep. Spacing between holes should be about 6 to 8 inches
apart along the length of the log, and about 2 inches apart around the
circumference of the log. (see diagram) This spacing is because the
mycelium grows faster parallel to the wood grain than against the wood
grain. It is tempting to space plugs farther apart to make the spawn
go farther, and you may have success doing this, but keep in mind that
this would extend the time until first fruiting, and would increase
the chance that a competing fungus would become established. Insert
1 plug into each hole so that it is flush with the inner bark. Tap them
with a rubber hammer to make them go in. Cover each hole and the log
ends with melted wax - this creates a moisture-tight seal so the mycelium
doesn't dry out; if you are conducting your inoculations on wet logs
you will need to let the log surface dry before applying the hot wax.
Cheese wax and beeswax work well for this purpose because they have
low melting points and can be purchased in quantity.
Care and Feeding
Your logs need to remain slightly moist, so keep them in the shade and
water them if they haven't been rained on for over a week or two.
To induce fruiting
The two primary factors that affect the timing of fruiting are temperature
and moisture; temperature signals the appropriate season for fruiting,
and moisture is necessary for the mycelium to produce a substantial
fruiting body. If you expose your logs to the weather and help them
through droughts, they will eventually fruit when conditions are right,
but many species can be forced into fruiting after they have colonized
a log by soaking them in a cool water bath overnight.