Making up the mushroom beds.
The place in the cellar, shed, house,
or elsewhere, where we intend to grow the mushrooms,
should be in readiness as soon as the manure has been
well prepared and is in proper condition for use.
The bed or beds should be made up at once. The
thickness of the beds depends a good deal upon circumstances,
such as the quality of the manure, whether
it is plain horse manure, or manure and loam mixed
together, or whether the beds are to be
made in heated or unheated buildings, and on the floor
or on shelves. Floor beds are generally nine
to fifteen inches deep; about nine inches in the case
of manure alone, in warm quarters, and ten to fourteen
inches when manure and loam are used. In cool
houses the beds are made a few inches deeper than
this so as to keep up a steady, mild warmth for a
long time. The beds may be made flat, or ridged,
or like a rounded bank against the wall; but the flat
form is the commonest, and the most convenient where
shelves are also used in the same building. Shelf
beds are generally nine inches deep; that is, the depth
of one board.
In making up the beds, bring in the
manure and shake it up loosely and spread it evenly
over the bed, beating it down firmly with the back
of the fork as you go along, and continue in this
way until the desired depth is attained. If it
is a floor bed and there is no impediment, as a shelf
overhead, tread the manure down firmly and evenly;
if the manure is fairly dry and in good condition
it will be pretty firm and still springy, but if it
is too moist and poorly prepared treading will pack
it together like wet rotten dung.
Now pierce a hole in the bed and insert
a thermometer. There are “ground”
or “bottom-heat” thermometers, as gardeners
call them, for this purpose, but any common thermometer
will do well enough; and after two or three days examine
this thermometer daily to see what is the temperature
of the manure in the bed. In roomy or airy structures
or where only a small bed has been made it may, in
the meantime, be left in this condition. But
in a tight cellar I find that the warm moisture arising
from the bed condenses in the atmosphere and settles
on the top of the manure, making it perfectly wet.
In order to counteract this, as soon as the bed is
made up I spread some straw or hay over it loosely;
the moisture settles on the covering and does not reach
through to the manure. Beware of overcovering,
as such induces overheating inside the bed. At
spawning time remove this covering. The bed will
then have become so cool (80 deg. or 90 deg.)
that there is very little evaporation from it, consequently
little danger of surface-wetting.
The Proper Temperature.- This,
in mushroom beds, depends upon the materials of which
they are composed, their thickness, how they are built,
the situation they are in, and other circumstances.
If the manure was good and fresh to begin with, carefully
prepared and used as soon as ready, the bed in a few
days will warm up to 125 deg., or a little more
or less, and this is very good. My best beds
have always shown a maximum heat of between 120 deg.
and 125 deg.. Had the manure been used a
few days too soon the heat would rise higher, perhaps
to 135 deg., but this is too warm; in this case
I would fork over the surface of the bed a few inches
deep to let the heat escape, and after a couple of
days compact the bed again. Boring holes all
over the surface of the beds with a crowbar is the
common way of reducing a too high temperature, and
when the heat has subsided sufficiently fill up these
holes with finely pulverized dry loam. With loam
we can fill them up perfectly, but we can not do this
with manure, and if left open they remain as wet sweat
holes that are very deleterious to the spreading spawn.
A too high temperature in the beds
should be sedulously guarded against, for it wastes
the substance of the manure, dries up the interior
of the bed, and the mushroom crop must necessarily
be starved and short.
Provided that the manure is fresh
and good and has been well prepared, if the beds,
after being made up, do not indicate more than 100
deg. or 110 deg. no alarm need be felt,
for excellent crops will likely be produced by these
beds. The thicker the beds are the higher the
heat will probably rise in them. Firmly built
beds warm up more slowly than do loosely built ones,
and they keep their heat longer. If the materials
are quite cool when built solidly into beds they are
not apt to become very warm afterward. But I
always like to make up the beds with moderately warm
manure.
It sometimes happens that circumstances
may prevent the making up of the beds just as soon
as the manure is in prime condition, and even after
they are made up the heat does not rise above 75 deg.
or 80 deg.. In such a case if the manure
is otherwise in good condition and fresh, it is well
enough and a good crop may be expected. But if
the manure, to begin with, had been a little stale,
rotten and inert, I certainly would not hesitate to
at once break up the bed, add some fresh horse droppings
to it, mix thoroughly, then make it up again.
Or a fair heat may be started in such a stale bed
by sprinkling it over rather freely with urine from
the barnyard, then forking the surface over two or
three inches deep and afterward compacting it slightly
with the back of the fork. Spread a layer of
hay, straw, or strawy stable litter a few inches deep
over the bed till the heat rises. If the manure
had been moist enough this sprinkling should not be
resorted to, but the fresh droppings added instead.
When it is applied, however, great care should be taken
to prevent overheating; a lessening or entire removal
of the strawy covering, and again firmly compacting
the surface of the bed will reduce the temperature.
Some saltpeter, or nitrate of soda, an ounce to three
gallons of liquid, will encourage the spread of the
mycelium after the spawn is inserted; a much stronger
solution of these salts can now be used than would
be safe to apply after the mycelium is running in the
bed.
When loam and manure mixed together
comprise the materials of which the bed is made, the
temperature is not likely to rise so high as when
manure alone is used, but this matters not so long
as the materials of which the bed is composed are
sweet and fresh and not over-moist. But if the
materials are cold and stale treat as recommended for
a manure bed, always bearing in mind that it is better
to have a cold bed that is fairly dry than one that
is wet, or, indeed, a warm one that is wet.
Mr. Withington, of South Amboy, has
a good word to say for beds of a low temperature.
He writes me: “Our beds kept in good bearing
two months, though they have borne in a desultory
way a month longer. Our best bed this season
was one that was kept at an even temperature.
The manure never rose above 75 deg. when made
up, and decreased to about 60 deg. soon after
spawning. Kept the house at 55 deg..”