Read CHAPTER XVI of Mushrooms: how to grow them a practical treatise on mushroom culture for profit and pleasure , free online book, by William Falconer, on ReadCentral.com.

Watering mushroom beds.

If the beds get dry they should be watered, for mushrooms will not grow well in dry beds or in a dry atmosphere. Watering is an operation requiring much care. In properly-made beds the manure should remain moist enough from first to last, and whatever dryness is evident should be in the loam casing of the beds and the atmosphere. In all artificially heated mushroom houses the beds and atmosphere are apt to get too dry at one time or another; in underground houses or cellars this is less apparent than in above-ground structures; in shaded north-facing houses dryness is less troublesome than in houses more openly placed.

Endeavor by all fair means to lessen the necessity for watering the beds, but when water is needed never hesitate to give it freely. Mulching the beds and maintaining a moist atmosphere are the best preventives. After the beds are spawned and molded it is a good plan to cover them with a light coating of strawy litter or hay to prevent drying, but this mulching should be removed when it is near time for the young mushrooms to appear. A light sprinkling of water over this mulching every few days, but never enough to reach the soil, assists in preserving enough moisture in the bed under the mulch and also in the atmosphere of the house.

Clean, soft water at a temperature of 80 deg. or 90 deg.; a little warmer or a little colder will not hurt, but do not use water higher than 110 deg., as it might injure the little pinheads, nor lower than the average temperature of the house, as it would chill the bed, and this should always be avoided.

Use a small or medium-sized watering pot with a long spout and a fine rose sprinkler. Apply the water in a gentle shower over the bed, mushrooms and all, but never use enough to allow it to settle in pools or run off in little streams. Clean water sprinkled over the mushrooms does not appear to hurt them, but they should never be touched with manure water, as it stains them. Just as soon as the surface of the bed shows signs of dryness give it water, the quantity depending upon the condition of the bed. Never let a bed get very dry before watering it. To thoroughly moisten a very dry bed requires a heavy watering; so much, indeed, that the sudden change might injuriously affect the young mushrooms and spawn. Give enough water at a time to moderately moisten the soil, not to soak it, but never sufficient to pass through the soil into the manure. Clean water only should be used until the beds come into bearing, but after that time manure water may be employed with advantage; however, this is not at all imperative; indeed, excellent crops can be and are continually being produced without the aid of manure water at all.

In the case of beds in full bearing, manure water is beneficial to the crop. Apply it from a small watering pot with a long narrow spout but no rose, and pour the liquid on gently over the surface of the bed, running it freely between the clumps but never touching any of the mushrooms. For this reason a rose should not be used.

I have always used manure water for mushrooms more or less, but during the past two seasons ’87-’88 and ’88-’89 I have experimented with it continuously and very carefully, using it in some form or other on part of every bed, and am satisfied that manure water made from fresh horse droppings is the best, and the dark colored liquid, the drainings from manure piles, is the poorest; in fact, this latter is not as good as plain water, for it seems to have a deadening rather than quickening effect upon the beds. Cow manure and sheep manure make a good liquid manure, but still I prefer the horse manure, and although having given hen and pigeon manure and guano fair tests I am not satisfied that they have benefited the crop, and there is always a risk in their use. Liquid manure made from the contents of the barnyard tank has not done much good, but fresh urine from the horse and cow stables diluted twelve to fifteen times its bulk has given favorable results.

Mushrooms not only bear with impunity but appear to enjoy a stronger liquid manure more than do any other cultivated plants, and I am satisfied that the weak liquids usually recommended for pot and garden plants would be barely more efficacious than plain water for mushrooms.

The manure water that has given me most satisfaction is prepared as follows: Dump two bushels of fresh horse droppings into a forty-five gallon barrel and fill up with water; stir it up well and let it settle over night. Drain off the liquid the next day and add a pound of saltpeter to it. For use, to a pailful of this liquid add a pailful of warm water. Water of about 80 deg. to 90 deg. is best for mushroom beds. Saltpeter is an excellent fertilizer for mushrooms. I use it in two ways, namely: First, powdered and mixed in the soil for casing the beds, at the rate of two ounces of saltpeter to the bushel of earth. Second, dissolved in water at the rate of two ounces of saltpeter to eight gallons of water, and sprinkled over the beds.

Common salt I use as an insecticide and also as a fertilizer, and am satisfied that it proves beneficial in both ways. Sometimes I sprinkle it broadcast on the surface of the beds, always on the bare places, never touching the mushrooms, and leave it there for a day or two, then with a fine, gentle sprinkling of water wash it into the soil. This is to help destroy the anguillulae. As a fertilizer only dissolve four ounces of salt in ten gallons of water, and with this sprinkle the beds.

A too dry atmosphere can be remedied by sprinkling the floors, walls, or litter coverings on the beds with water, not heavily or copiously, but gently and only enough to wet the surfaces; better moisten in this way frequently than drench the place at any one time. But I very much dislike sprinkling the beds in order to moisten the atmosphere. An experienced man can tell in a moment whether or not the atmosphere of the mushroom house is too dry. The air in the mushroom house should always feel moist, at the same time not raw or chilly, and the floor and wall surfaces should present a slow tendency to dry up, and the earth on the beds should retain its dark, moist appearance. The least tendency to dryness should at once be relieved by damping the wall and floor surfaces.

In houses heated by smoke flues, or still more by ordinary stoves and sheet iron pipes, it may be necessary to dampen the floors and walls once or several times a day to maintain a sufficiently moist atmosphere, but where hot water pipes are used and the houses are tight enough to require but little artificial heat, such frequent sprinkling will not be necessary. In the case of beds in unheated structures the ordinary atmosphere is generally moist enough.

Manure Steam for Moistening the Atmosphere.- The late James Barnes, of England, a grand old gardener, writing in the London Garden, Vol. III, page 486, describes his method of growing mushrooms sixty years ago, and says: “In winter a nice moist heat was maintained by placing hot stable manure inside, and often turning it over.” Mr. John G. Gardner, of Jobstown, N. J., is one of Mr. Barnes’s old pupils and a most successful mushroom grower, and he now practices this same method of moistening the atmosphere by hot manure steam. See page 21.

In damping the floors of the mushroom house, as well as the beds, I use a medium-sized watering pot and fine rose; but in sprinkling the walls and other parts not readily accessible by the watering pot I use a common garden syringe.