Loam for the beds.
In growing mushrooms we need loam
for casing the beds after they are spawned, topdressing
the bearing beds when they first show signs of exhaustion,
filling up the cavities in the surface of the beds
caused by the removal of the mushroom stumps, and
for mixing with manure to form the beds. The
selection of soil depends a good deal on what kind
of soil we have at hand, or can readily obtain.
The best kind of loam for every purpose
in connection with mushroom-growing is rich, fresh,
mellow soil, such as florists eagerly seek for potting
and other greenhouse purposes. In early fall I
get together a pile of fresh sod loam, that is, the
top spit from a pasture field, but do not add any
manure to it. Of course, while this contains a
good deal of grassy sod there is much fine soil among
it, and this is what I use for mushrooms. Before
using it I break up the sods with a spade or fork,
throw aside the very toughest parts of them, and use
the finer earthy portion, but always in its rough
state, and never sifted. The green, soddy parts
that are not too rough are allowed to remain in the
soil, for they do no harm whatever, either in arresting
the mycelium or checking the mushrooms, and there
is no danger that the grass would grow up and smother
the mushrooms.
Common loam from an open, well-drained
fallow field is good, and, if the soil is naturally
rich, excellent for any purpose. But do not take
it from the wet parts of the fields. Reject all
stones, rough clods, tussocks, and the like.
Such loam may be used at once.
Ordinary garden soil is used more
frequently than any other sort, and altogether with
highly satisfactory results. The greatest objection
I have to it is the amount of insects it is apt to
contain on account of its often repeated heavy manurings.
Roadside dirt, whether loamy or gritty,
may also be used with good results. If free from
weeds, sticks, stones and rough drift, it may be used
at once, but it is much better to stack it in a pile
to rot for a few months before using.
Sandy soil, such as occurs in the
water-shed drifts along the roads and where it has
been washed into the fields, is much inferior to stiffer
and more fibrous earth.
I have used the rich dark colored
soil from slopes and dry hollows in woods, and, odd
though it may appear, as mushrooms do not naturally
grow in woods, with success. But it is not as
good as loam from the open field.
Peat soil or swamp muck that has been
composted for two or three years has failed to give
me good returns. The mushrooms will come up through
it all right, but they do not take kindly to it.
Heavy, clayey loam is, in one way,
excellent, in another, not so good. So long as
we can keep it equably moist without making it muddy
it is all right, but if we let it get a little too
dry it cracks, and in this way breaks the threads
of the spawn and ruins the mushrooms that were fed
through them.
Loam Containing Old Manure.- Loam
in which there is a good deal of old, undecomposed
manure, such as the rich soil of our vegetable gardens,
is unqualifiedly condemned by some writers because
of the quantity of spurious and noxious fungi it is
supposed to produce when used in mushroom beds.
But I can not join in this denunciation because my
experience does not justify it. This earth is
the only kind used by many market gardeners, as they
have no other, and certainly without apparent injurious
effect. When I was connected with the London market
gardens, some twenty years ago, Steele, Bagley, Broadbent,
and the other large mushroom growers in the Fulham
Fields cased all of their beds with the common garden
soil perhaps the most manure-filled soil
on the face of the earth and spurious fungi
never troubled them. Indeed, I can not understand
why it should produce baneful crops of toadstools when
used in mushroom beds, and no toadstools when used
for other horticultural purposes, as on our carnation
benches in greenhouses, in our lettuce or cucumber
beds, or in the case of potted plants. True, spurious
fungi may appear in the earth on our greenhouse benches
or frame beds or mushroom beds at any time and in
more or less quantity, but I am convinced that the
rich earth of the vegetable garden has no more to do
with producing toadstools than has any other good
soil, and old manure has far less to do with it than
has fresh manure.
All practical gardeners know how apt
hotbeds, in spring when their heat is on the decline,
are to produce a number of toadstools; and, also,
that when the bed is “spent,” that is,
when the heat is altogether gone, the tendency to
bear toadstools has gone too. This peculiarity
is more apparent in spring than in fall. All
mushroom growers know that spurious fungi, when they
appear at all, are most numerous three to two weeks
before it is time for the mushrooms to come in sight.
The same growth appears in the manure piles out in
the yard; a few weeks after the strong heat of the
manure has gone lots of toadstools may be observed
on and about the heaps, but on the piles of well-rotted
cold manure we seldom find toadstools at all.
The fresh, clean stable manure used
in mushroom-growing is not apt to be charged with
the spores of pernicious toadstools; their presence
is always most marked in the case of mixed manures.
And there is a current idea that mushrooms
will not thrive in beds in which old manure abounds,
either in the loam or fermenting material; that it
kills the mycelium. This, too, I must refute.
I have seen heavy crops of spontaneous mushrooms come
up in violet and carnation beds in winter, and where
the soil consisted of at least one-fourth of rotted
manure well mixed with the earth. In cucumber
and lettuce beds the same thing has taken place.
And in similar beds that have been planted artificially
with spawn, good crops of mushrooms have also been
raised, and the mycelium, instead of evading the lumps
of old manure in the soil often forms a white web
right through them.