SPAWNING THE BEDS.
After the mushroom bed is made up it should, within a few days, warm to
a temperature of 110° to 120°. Carefully observe this, and never spawn a
bed when the heat is rising, or when it is warmer than 100°, but always
when it is on the decline and under 90°. In this there is perfect
safety. Have a ground thermometer and keep it plunged in the bed; by
pulling it out and looking at it one can know exactly the temperature of
the bed. Have a few straight, smooth stakes, like short walking canes,
and stick the end of these into the bed, twelve to twenty feet apart; by
pulling them out and feeling them with the hand one can tell pretty
closely what the temperature of the bed is.
All practical mushroom growers know that if the temperature of a twelve
inch thick bed at seven inches from the surface is 100°, that within an
inch of the surface of the bed will only be about 95° indoors, and 85°
to 90° out of doors. Also, that when the heat of the manure is on the
decline it falls quite rapidly, five, often ten degrees, a day, till it
reaches about 75°, and between that and 65° it may rest for weeks.
Some years ago I gave considerable attention to this matter of spawning
beds at different temperatures. Spawn planted as soon as the bed was
made (five days after spawning the heat in interior of bed ran up to
123°) yielded no mushrooms, the mycelium being killed. The same was the
case in all beds where the spawn had been planted before the heat in the
beds had attained its maximum (120° or over). Where the heat in the
middle of the bed never reached 115°, the spawn put in when the bed was
made, and molded over the same day, yielded a small crop of mushrooms. A
bed in which the heat was declining was spawned at 110°; this bore a
very good crop, and at 100° and under to 65° good crops in every case
were secured, with several days' delay in bearing in the case of the
lowest temperatures. But notwithstanding these facts, my advice to all
beginners in mushroom growing is, wait until the heat of the bed is on
the decline and fallen to at least 90°, before inserting the spawn.
Writing to me about spawning his beds, Mr. Withington, of New Jersey,
says: "I believe a bed spawned at 60° to 70°, and kept at 55° after the
mushrooms appear, will give better results than one spawned at a higher
temperature, say 90°."
[Illustration: FIG. 23. BRICK SPAWN CUT IN PIECES FOR PLANTING.]
=Preparing the Spawn.=--If brick spawn is used cut up the bricks
(standard size) into ten or twelve pieces with a sharp hatchet, and
avoid, as much as possible, making many crumbs, as is the case generally
when a hammer or mallet is used in breaking the bricks. Extra large
pieces of spawn are apt to produce large clumps of mushrooms, but this
is not always an advantage, as when many mushrooms grow together in a
clump they are apt to be somewhat undersized, and in gathering we can
not pluck them all out clean enough so as not to leave a part of the
"root" in the ground to poison the balance of the clump, in cases where
several or many of them spring from one common base.
=Inserting the Spawn.=--When brick spawn is used plant the lumps about
an inch deep under the surface of the manure, and about ten inches apart
each way. If the spawn looks very good, and the lumps are large do not
plant them quite so close as when the spawn shows less mycelium in it,
and the lumps are small. Never use a dibber in planting spawn; simply
make a hole in the manure with the fingers, insert the lump and cover it
over at once, and as soon as the bed has been planted firm it well all
over. Although the lumps are buried only an inch deep under the manure,
we have to make a hole three or four inches deep to push the lump into
to get it buried.
French or flake spawn is inserted in much the same way and at about the
same distance, only, instead of cutting it up into lumps, we merely
break it into flaky pieces about three inches long by an inch thick, and
in planting it in the beds, in place of pushing it into the hole, lay in
the flake on its flat side and at once cover it.
Many growers plant spawn a good deal deeper than I do, but I have never
found any advantage in deep planting. In moderately warm beds, or beds
that are likely to retain their heat for a considerable time, I am
satisfied that shallow planting is better than deep planting. When we
want to mold over our beds soon after spawning them, shallow planting is
to be recommended. But if the beds are only 75° to 78°, before being
spawned; then I think deep planting is better than shallow planting,
because the genial temperature gives the mycelium a better start in life
than would the cooler manure nearer the surface.
If there is any likelihood of the surface manure getting wet from the
condensed moisture of the atmosphere, I would again cover over the beds
with some hay or straw, and let it remain on until molding time. And if
the bed is a little sluggish,--that is, cool,--this covering will help
in keeping it warm. Outside beds should be molded over in three or four
days after spawning; inside beds in eight to ten days.
=Steeped Spawn.=--As brick spawn is so hard and dry I have tried the
effect of steeping it in tepid water before planting; some pieces were
merely dipped in the water, and others allowed to soak in the pails
one-half, one, five, and ten hours. The effect was prejudicial in every
instance and ruinous in the case of the long-soaked pieces.
=Flake Spawn.=--"This is produced by breaking up the brick spawn into
pieces about two inches square and mixing them in a heap of manure that
is fermenting gently. After lying in this heap about three weeks it will
be found one mass of spawn, and just in the right condition for running
vigorously all through the bed in a very short time.... When flake spawn
is used the appearance of the crop is from two to three weeks earlier
than when brick spawn is used."--Mr. Henshaw, in first edition of
"Henderson's Handbook of Plants." I have tried this method and given it
careful attention, but the results were inferior to those obtained where
plain, common brick spawn had been used at once.
In all my practice I have found that any disturbance of the spawn when
in active growth which would cause a breaking, exposing, or arresting of
the threads of the mycelium has always had a weakening influence upon
it. I have transplanted pieces of working spawn from one bed to another,
as the French growers do, but am satisfied that I get better crops and
larger mushrooms from beds spawned with dry spawn than from beds planted
with working spawn from any other beds.