Casing is the easiest way to improve your
technique and increase your yields, but it's also a source of a lot of
headaches and questions until you get the hang of it.
The biggest source of casing problems seem to come from over-
or total colonization of the casing surface. Discussed at length in
Mushroom Cultivator, the casing layer serves
three main purposes:
- To protect the colonized substrate from drying out.
- To provide a humid microclimate for primordial formation and
- To provide a water reservoir for the maturing mushrooms.
Overlay is the condition which results when
mycelium has been allowed to completely cover the casing surface. It is caused
by prolonged vegetative growth temperatures, high CO2 levels, and excessive
humidity. If over watered, the overlay will become matted,
or, will form a dense, dead layer of cells on the casing surface.
A casing showing signs of overlay will begin
to shrink and pull away from the sides of the container. It will also become
unreceptive to water, and puddles may form on the surface after misting. If any
pinheads form, they will likely do so at the edges of the casing. Most of the
pinheads will abort, and only a few mushrooms will fully mature. Once
this has happened, the casing layer really isn't a casing layer anymore. It is
no longer serving it's three main functions, and has in essence become a second
layer of non-nutritious substrate.
As previously mentioned, overlay is caused by prolonged
vegetative growth temperatures, high CO2 levels, and excessive humidity. It
results when the grower does not take the proper steps to initiate pinning, or,
when the grower initiates the pinning strategy too late. As a general rule of
thumb, the initiation process should begin as soon as mycelium is first visible
in the valleys of the casing layer (or, when you can just barley make it out
underneath the surface of the casing). However, Psilocybes Cubensis is a species
which enjoys high mycelia momentum. Even after initiation of the pinning
process, the mycelium will continue to grow for a period of time and consume
more of the casing. This is why timing is critical.
1. Temperature & Cold Shocking
According to The Mushroom Cultivator,
the ideal temperature for Psilocybes Cubensis during colonization of the
substrate and initial colonization of the casing layer is 84-86 degrees
Fahrenheit. A 10 degree drop in temperature to 74-78 degrees Fahrenheit is
generally enough to initiate the pinning process.
This technique is a little more extreme however. It involves cold shocking
the casing by covering the tray with tin foil and placing it in the refrigerator
for 24 hours prior to birthing into the fruiting terrarium. This cold shock
really let's the mycelium knows it's time to fruit, and may serve to not only
increase the size of the first flush, but also slow the previously mentioned mycelia
momentum. The jury is still out on this one however... Some growers
have expressed concerns regarding the bacterial count in their household fridge,
while others persist that it's not necessary.
My advice is to try the 10 degree drop first. If that works for you, then
stick with it. If however you are still having problems (Perhaps you live in a
region where the temperature is too high to provide a 10 degree drop in
temperature?), give the cold shock a try; it might just do the trick.
2. High CO2 Levels
The second trigger that lets the mycelium know it's time to
fruit is a reduction in CO2 levels in the atmosphere. This can simply be
achieved by ensuring that you are fanning your terrarium at least once a day
(2-3 times per day may be necessary depending on the size of the terrarium and
how many casing trays are inside). Another idea is to incorporate some natural
flora into your terrarium, such as a dedicated tray of rye grass that is just
there to grow and regulate your atmosphere for you.
3. Excessive Humidity
Generally, casings do not require as much humidity as cakes because it's the
casing layer itself that creates the microclimate favorable to pinhead formation
and development. As the mushrooms grow, they draw moisture from the casing layer
as well as the atmosphere. That being said, the use of cool mist or ultrasonic
humidifiers, or perlite humidification, may be too much for your casings.
For the most part, what you use to humidify is going to depend on where you
live. If you live in an area where the ambient humidity is generally high, you
will probably be able to get away with just a couple of misting per day. If
however, you live in an area where the overall humidity is quite low (Where I
live, it gets down to about 30% during the winter) you may need to use perlite
or a humidifier setup. The key to remember is that if your casing continues
vegetative growth and develops overlay after you've initiated the pinning
strategy, your humidity may be too high.
Psilocybes Cubensis is a photosensitive mushroom, meaning
certain spectra of light are necessary for pinhead formation and development.
Ps. Cubensis responds best to light heavy in the blue- and ultra-violet
spectrums, specifically which peak at 370, 440, and 460 nanometers. Red,
infra-red, and green light on the other hand are ineffective at initiating
pinheads. A few hours of light per day is really all that is needed. If you can
see the casings then you are doing fine. Just remember that mushrooms are not
like the pot plant that's in your closet; they won't grow bigger or faster with
more light :-)