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.
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."