made deeper in a cool shed than in a cellar or warm
mushroom house, so that they may retain their heat for a long time.

Shelf beds should not be used in unheated sheds, because of the
difficulty in keeping them warm in winter. As a rule, shelf beds are not
made as deep as are those upon the floor; hence they do not hold their
heat so long. When cold weather sets in it is easy to box up and cover
over the lower beds to keep them warm, but in the case of shelf beds,
that are exposed above and below, it is more trouble to protect them
sufficiently against cold than they are worth.

Generally speaking, the term shed is applied to unheated, simple wooden
structures; for instance, the wood-shed, the tool-shed, a
carriage-house, or a hay-barn. But we often use the name shed to
designate heated buildings, as the potting and packing sheds of
florists. Were it not that these heated sheds are simply workrooms, and
where there is a great deal of going out and in, and, consequently,
draughts and sudden and frequent fluctuations of temperature, the
treatment of mushroom beds made in them would be the same as that
advised for regular mushroom houses; but as the circumstances are
somewhat different the treatment, too, should not be the same. A warm
potting shed is an excellent place for mushroom beds. Here they should
be made under the benches and covered up in front with thick calico,
plant-protecting cloth, or light wooden shutters, to exclude cold
currents and sudden atmospheric changes, and guard against the beds
drying too quickly.

CHAPTER V.

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 deg. or 50 deg. in
winter, while hothouses run from 60 deg. to 70 deg. at night, with a rise of ten
to twenty degrees by