GROWING MUSHROOMS IN GREENHOUSES.
Any one who has a greenhouse can grow mushrooms in it. And it does not
matter what kind of greenhouse it is, whether a fruit house, a flower
house, or a vegetable house, it is available for mushrooms. One of the
advantages of raising mushrooms in a greenhouse is that they grow to
perfection in parts of the greenhouse that are nearly worthless for
other purposes; for instance, under the stages, where nothing else grows
well, although rhubarb and asparagus might be forced there, and a little
chicory and dandelion blanched.
[Illustration: FIG. 11. BOXED MUSHROOM BED UNDER GREENHOUSE BENCH.]
Cool greenhouses, in all cases, are better for mushrooms than hothouses.
Cool houses are seldom kept at a lower temperature than 45° or 50° in
winter, while hothouses run from 60° to 70° at night, with a rise of ten
to twenty degrees by day, and this is too hot for mushrooms. It is a
very easy matter, by means of covering with hay or boxing over and
covering the boxing with hay or matting, to keep a mushroom bed in a
cool house warm and free from marked changes in temperature; but it is a
difficult matter to keep a mushroom bed in a hothouse cool enough and
prevent sudden rises in temperature.
=On Greenhouse Benches.=--It sometimes happens that the beds are formed
on the greenhouse benches, and the mushrooms occupy the same place that
might be assigned to roses or any other planted-out crop. The beds on
the benches are made one board deep, that is, eight to ten inches of
short, fresh manure, and otherwise as in the case of beds anywhere else.
After the beds are spawned and cased with soil, by covering them over
with a layer of straw litter or hay, sudden drying out of the surface is
prevented, and in order to further prevent this drying it is a good plan
to sprinkle some water over the mulching every day or two, but not
enough to soak through into the bed. About the time the young mushrooms
commence to show themselves, remove the mulching and replace it with a
covering of shutters raised another board's height above the bed, or
with strong calico or plant-protecting cloth hung curtain-fashion over
the beds. The accompanying illustration, Fig. 12, for which I am
indebted to Henry A. Dreer, of Philadelphia, gives an excellent idea of
how mushrooms may be grown and cared for on greenhouse benches. This
illustration, Mr. Dreer writes: "is made from a photograph of a crop
grown on the greenhouse benches at the Model Farm, by Mr. McCaffrey,
gardener to J. E. Kingsley, Esq., of the Continental Hotel.... No
covering of litter is used, but the requisite shading on sunny days is
secured by the use of cotton cloth stretched over the top of the bed, as
shown in the engraving."
[Illustration: FIG. 12. MUSHROOMS GROWN ON GREENHOUSE BENCHES AT MR. J.
E. KINGSLEY'S MODEL FARM.]
My principal objection to mushroom beds on greenhouse benches is their
liability to frequent and marked changes of atmospheric temperature and
moisture, and to drying out. In midwinter they may be all right, but as
spring advances and the sun's brightness and heat increase, the
susceptibility of the beds to become dry also increases.
[Illustration: FIG. 13. WIDE BED WITH PATHWAY ABOVE.]
=In Frames in the Greenhouses.=--Mr. J. G. Gardner has a range of
greenhouses some 900 feet long--the longest unbroken string of
glasshouses that I know of--for the forcing of fruit and vegetables in
winter; grapes, peaches, nectarines, figs, tomatoes, cucumbers, snap
beans, peas, lettuce. This range is divided into several compartments,
to accommodate the different varieties of crops, also so that some can
be run as succession houses. In order to make the most of everything,
market-gardener-like, he doubles up his crops wherever possible, and for
this end he finds no crop more amenable and profitable than mushrooms.
It matters nothing to him whether the house is cold or warm, he can grow
mushrooms in it anyway, and in order to be master of the situation he
makes his mushroom beds in hotbed frames inside the greenhouses. By
attending to ventilating or keeping close, or covering up or leaving
bare, he can properly regulate the temperature of the mushroom bed, no
matter how hot or cold the atmosphere of the greenhouse may be. In the
same way--by shading the panes or unshading them--he governs the light
admitted to the mushrooms.
The greenhouses in which the mushrooms are grown are orchard houses,
that is, glasshouses in which peach and nectarine trees are grown and
forced. As these trees fruit and finish their growth early, it is
necessary that they be kept as cool and inactive as possible in the fall
and early winter, and started again into growth in late winter. In the
fall, therefore, the fermenting material being confined in frames
retains warmth enough for the proper development of the mushrooms, and
as the winter advances and the heat in the frames begins to wane it
becomes necessary to begin heating the greenhouses in order to start the
trees into bloom and growth, and thus are provided very favorable
conditions for the continued production of the mushroom crop.
[Illustration: FIG. 14. MUSHROOMS ON GREENHOUSE BENCHES UNDER TOMATOES.]
The frames used are common hotbed box frames seven feet wide and
carrying three and one-half feet wide sashes. A string of them is run
along the middle of the greenhouses, for greenhouse after greenhouse is
occupied by them. They are flat upon the floor, and in the early part of
the season alone in the greenhouses. But as the winter advances a
temporary staging is erected over these frames, on which spiræas, peas,
beans, or other flowers or vegetables are to be grown. These love the
light and a position near the glass, whereas the mushrooms grow
perfectly well in the dark quarters of the frames under the stages. If
he did not grow mushrooms under these stages the room would be
unoccupied, hence unproductive; but by occupying it with mushrooms he
not only gets peaches and snap beans at once out of the same greenhouse,
but also a crop of mushrooms, often worth as much as the other two.
In preparing the beds in the frames they were made up a foot deep, very
firm, and with New York stable manure brought direct from the cars.
There was no preliminary preparation of the manure. A layer of loam one
and one-half inches deep was then spread over the surface and forked
into the bed of manure one and one-half inches deep, so as to form an
earthy mat three inches deep. This was then packed solid with the feet,
and a two-inch layer of loose manure added all over. In about ten days
the temperature three inches below the surface was about 95°, and the
beds were then spawned. In spawning, drills were drawn across the beds
about a foot apart and just deep enough to touch but not penetrate the
earthy mat before referred to. The broken spawn was then sown in the
drills and covered with a layer of loam one and one-half to two inches
deep, which was tamped slightly. The sashes were then put on and tilted
up a little to let the moisture escape. By the time the mushrooms
appeared there was very little need of ventilating, as the condensation
of moisture on the glass was scarcely apparent; but ventilation is
easily guided by the appearance of moisture on the glass, the more of
this the more ventilation should be given. To begin with, there was no
attempt at shading the frames; but as soon as the mushrooms began to
appear the beds were shaded, and mostly by the crops of other plants on
the stages above them. These frame beds were made up last October, and
began bearing in December, and on March 14 Mr. Gardner wrote me: "The
mushrooms in my frames have done grandly. I cut large basketfuls to-day
of the finest mushrooms I have ever seen, some of them measuring five
inches in diameter before being fully expanded."
And further, in submitting the above notes to him for verification, he
adds: "There is one vital point we should impress upon all who grow
mushrooms in frames or under greenhouse benches, namely, that sudden
changes of temperature must be avoided. While light, in my opinion, is
good for mushrooms, it causes a rise of temperature, and this we must
guard against. In order to maintain a uniform temperature all glass
exposed to light or heat in any other way should be covered with some
non-conducting material. Rye straw is the best thing for this purpose
that I know of. Indeed, neglect of this simple matter, in cases where
sunlight and heat from hot-water pipes come in contact with the young
mushrooms or mycelium on the surface of the beds, is the cause of many
failures in growing in frames and greenhouses."
=Under Greenhouse Benches.=--Open empty spaces under the stages anywhere
are good places for mushroom beds. However, carefully observe a few
points, to wit: A dry floor under the beds is imperative, for a wet
floor soaks and chills the beds, and renders them unhealthy for the
spawn; but the common earth floor is good enough, provided water does
not stand upon it at any time; if it does, the floor to be under the
beds can be rendered dry by raising it a little higher than the general
level, or using a flooring of old boards. Beds should not be built close
up against hot-water pipes, steam pipes, or smoke flues, as the heat
from these when they are in working condition will bake the parts of the
beds next to them and render them unproductive, and also crack and spoil
the caps of the mushrooms that come up within a foot or two of the
pipes. But this injury from hot pipes and flues can be lessened greatly
by boxing the pipes, so as to shut off the heat from the mushroom beds
and allowing it full escape upward; then the beds can be made, with
safety, up to within a foot of the pipes. As a rule, hot-water pipes are
run around under the front benches of a greenhouse, then it would not be
advisable to make beds under those benches. The middle bench is the one
most commonly free from pipes, hence the one best adapted for beds. It
has more headroom, and therefore easier working facilities. Steam-heated
greenhouses generally present the best accommodations for mushroom beds,
because the pipes occupy less room under the benches than do those for
hot water, and they are always kept higher from the ground.
=Among Other Plants on Greenhouse Benches.=--It sometimes happens that
mushrooms spring up spontaneously among the roses, carnations, violets,
mignonette, and other crops that are grown "planted out" on the benches,
and this is particularly the case where fresh soil had just been used,
in whole or part, for filling the bench beds. These mushrooms come from
natural spawn contained in the loam or manure before they were brought
indoors, and which is apt to be true virgin spawn. The mushrooms are
generally of the common kind, grown from brick spawn, but occasionally a
much larger and heavier sort is produced, and this is the "horse"
mushroom. It is perfectly good to eat, only of coarser quality than the
other.
A fair and certain crop can be obtained by planting pieces of spawn in
the beds here and there between the plants and where they will be least
likely to be soaked with water. In order to further insure the
development of the spawn, holes about the size of a pint cup should be
scooped out here and there over the bed, and filled up solidly with
quite fresh but dry horse droppings, with the piece of spawn in the
middle, and covered over on top with an inch of loam, so as to leave the
whole surface of the bed level. So small a quantity of dry manure
surrounded with cold earth will not heat perceptibly, and the moisture
of the loam about it will soon moisten it, no matter how dry it may be.
The dry, fresh droppings are the very best material for starting the
mycelium into growth.
=Growing Mushrooms in Rose Houses.=--George Savage, the head gardener at
Mr. Kimball's greenhouses, Rochester, N. Y., grows mushrooms very
successfully under the benches of the rose houses. When he makes up his
earliest mushroom beds in the fall the rose house is kept cool, and this
is an advantage to the mushroom beds, which get all the warmth they need
from the fermenting manure; but as November advances, and the heat in
the beds begins to wane the rose houses are "started," and this
artificial warmth comes in good season to benefit the growing mushrooms.
The roses, in this case, are planted out on benches, hence there is
scarcely any dripping of water from above upon the mushroom beds below.
Mr. George Grant, of Mamaroneck, N. Y., who grows mushrooms in the
greenhouse, I called to see last January, and was very much pleased with
his simple and successful method. The beds were then in fine bearing,
very full, and the crop was of the best quality. The beds were made upon
the earthen floor of his tomato-forcing house and under the back bench.
The bed was flat, seven to eight inches deep, with a casing of a
ten-inch-wide hemlock board set on edge at the back, and another of same
size against the front. The bed was made of horse droppings, six inches
deep, and molded over with fresh loam one and one-half inch deep. Over
the whole, and resting on the edges of the hemlock boards, was a light
covering of other boards, with a sprinkling of hay on top of them to
arrest and shed drip, and maintain an equable temperature in the bed.
Mr. Abram Van Siclen, of Jamaica, Long Island, is one of the largest
mushroom growers for market in the country, as well as one of the most
extensive growers of market-garden truck under glass around New York. He
devotes an immense area under his lettuce-house benches to the
cultivation of mushrooms. The beds are made upon the floor in the usual
way, only for convenience' sake, to admit of plenty of room in making up
the beds and gathering the crop, besides avoiding the necessity for
building higher structures than the ordinary lettuce greenhouses, the
mushroom beds are sunken about eighteen to twenty-four inches under the
level of the pathways. As the lettuces are planted out upon the benches
there is very little drip from them, hence the sunken beds are well
enough. And the temperature of a lettuce house is about right for a
long-lasting mushroom bed. Light is excluded by a simple covering of
salt hay laid over the beds, and sometimes by light wooden shutters set
up against the aperture between the lettuce benches and the floor, in
this way boxing in the mushrooms in total darkness.
Mr. William Wilson, of Astoria, has an immense greenhouse establishment
near New York. In his greenhouses, under both the side and middle
benches, he grows mushrooms, and when I saw them in January there were
about 300 square yards of beds. The beds were flat, about nine inches
thick, built upon the ground, and protected from strong light by having
muslin tacked over the openings between the benches and the beds
alongside the pathways. But his crop was suffering from drip. Mr. Wilson
told me he could not begin to supply the demand. He says whatever he
makes on mushrooms is mostly clear gain. They occupy space that
otherwise would remain unoccupied, and he needs the manure and the loam
in his florist business, and it is in better condition for potting after
it has been rotted in the mushroom beds than it was before it was used
for this purpose.
[Illustration: FIG. 15. MR. WM. WILSON'S MUSHROOM BEDS.]
=Drip from the Benches.=--This must be prevented from the beds above,
else it will soak or chill, and in a large measure kill the spawn. I
have seen many examples of this evil. The beds would be full of drip
holes all over their surface, and although a good many mushrooms here
and there about the bed might perfect themselves, multitudes only reach
the pin-head condition--or possibly the size of peas--and then fogg off
in patches. It is not one or two little mushrooms in a clump that fogg
off, but where one foggs off all of the little ones in that patch go,
for it is not a disease of the individual mushroom, but of the mycelium
or mushroom plant that runs in the bed, and when this is injured or
killed all the little mushrooms arising from this particular patch of
plant are robbed of sustenance and must perish.
In greenhouses where the benches are occupied with roses, carnations,
bouvardias, violets, or lettuces, "planted out," as commercial florists
and gardeners generally grow them, there is very little drip, because
while the plants on these benches are freely watered, the soil is never
soaked enough for the water to drain from it in dripping streamlets, as
is continually the case in greenhouses where potted plants are grown on
the stages. Under these "planted out" benches, if care is exercised,
mushrooms can be grown in open beds; in fact, it is about the best place
and condition for them in a greenhouse.
[Illustration: FIG. 16. MUSHROOM BED BUILT FLAT UPON THE GROUND.]
With stages occupied by plants in pots provision needs to be made to
ward off the drip from the mushroom beds, by erecting over, and
conveniently high above them, a light wooden framework, on which rest
light wooden frames covered with oiled paper, oiled muslin, or
plant-protecting cloth. In fact, three light wooden strips run over the
bed, as shown in Fig. 12, or three strings of stout cord or wire run in
the same manner will answer for small beds, and act as a support for the
oiled muslin or plant-protecting cloth. Building paper is sometimes used
for the same purpose. Mr. J. G. Gardner uses ordinary hotbed frames and
sashes, as described in a previous chapter. Light wooden shutters--made
of one-half inch or five-eighths inch pine--may be used for the same
end, and will last for many years.
[Illustration: FIG. 17. RIDGED MUSHROOM BED.]
The beds under the greenhouse benches may be made up in the same way as
are beds anywhere else; that is, flat upon the floor and between two
boards set on edge, as seen in Fig. 16, or in ridges under the high or
middle benches, as in Fig. 17, or in banked beds against the back wall,
as shown in Fig. 18. Generally the flat bed is the most convenient to
make and take care of.
[Illustration: FIG. 18. BANKED BED AGAINST A WALL.]
In open, airy greenhouses it is always well to inclose the mushroom beds
in box casings and with sash or shutter coverings, to prevent draughts
and fluctuations of temperature and atmospheric moisture. This can
easily be done by making the sides a board and a half (fifteen inches),
or two boards (twenty inches) high, and covering over with light wooden
shutters, sashes, or muslin or paper-covered light frames. See Fig. 11.
=Ammonia Arising.=--Ammonia arising from the manure of the mushroom beds
in the greenhouse may be injurious to the other inmates of the
greenhouse. If the manure has been well prepared before it was
introduced into the greenhouse, the ammonia arising from it will not, in
the least degree, injure any other plants or flowers that may be in the
house; but if the manure is fresh, hot, and rank, the opposite will be
the case. Beds in greenhouses should always be made up of manure that
has been well prepared beforehand out of doors or in a shed, and as it
is brought into the greenhouse it should at once be built solidly into
the beds. Then very little steam will arise from the beds; in fact, it
will be imperceptible to sight or smell.