The seedsmen import it from Europe every year along with their seeds. A prominent Boston seedsman writes me: "We get our supply through the London wholesale seedsmen, for the sake of convenience and cheaper ocean freight, etc. Coming with a shipment of other goods and on same bill of lading brings the freight charges down. The low price at which mushroom spawn is sold in quantity can only be maintained with low freight rates, as there is a duty here of 20% on the article."
Fig. 21. Brick Spawn.
By direct inquiry of the leading importers in different cities I find that we import about 4500 lbs of French or flake spawn, and 4000 bushels, or 64,000 lbs of English or brick spawn, and that fully a half of this whole importation is handled by the seedsmen of New York city. In New York one firm alone, who make a specialty of supplying market gardeners, has in one year imported 1500 bushels of brick spawn. But the vicinity of New York is the great mushroom-growing center of the country, also the best market for mushrooms in the country. One gardener at Jamaica, L. I., bought 1000 lbs of brick spawn at one time, and a neighbor of his bought 400 lbs; this shows what a large quantity of spawn market gardeners require. And the demand this year is unprecedented; some of our leading importers had sold out their supply before the first of November. And it is not private growers so much as market growers who are the cause of this; the market men find there is money in growing mushrooms and they are going into it.
Spawn comes in the form of dry, hard, solid manure bricks, and also in the form of flakes of half rotted strawy manure. These bricks and flakes are completely permeated with the mushroom mycelium.
The brick spawn is commonly known as English spawn, and what is imported into this country is made in England, mostly about London. The bricks made by the different manufacturers vary a little in size and weight; in some cases ten bricks go to the bushel, in others fourteen, and in others sixteen. This last is the commonest sized brick, and weighs exactly a pound, and measures about eight and one-half inches long, five and one-fourth inches wide, and one and one-fourth inches thick; it is what the London spawn makers call a 9x6x2 inch brick, but it shrinks in drying. In retailing brick spawn in this country it is sold by weight and not by measure.
Mill-track mushroom spawn is advertised by some of our seedsmen, but what they sell under this name is only the ordinary English brick spawn. One of our prominent seed firms who advertise it write me: "Genuine mill-track spawn used to be the best in England, but it has been superseded, although European gardeners still call for English spawn under the name of 'mill-track.'" The real mill-track spawn is the natural spawn that has spread through the thoroughly amalgamated horse droppings in mill-tracks or the cleanings from mill-tracks. It is usually sold in large, irregular, somewhat soft lumps, and is much esteemed by spawn makers for impregnating their bricks, but nowadays, that horses have given place to steam as a motive power in mills, we have no further supply of mill-track spawn for use in spawning our mushroom beds. We do not feel this loss, however, as the spawn now manufactured by our best makers will produce as good a crop of mushrooms as the old mill-track natural spawn used to do.
The flake spawn is what is generally known as French spawn, and is imported into this country from France. But the manufacture of "French" spawn for sale, however, is not strictly confined to France. It is put up in two ways, namely, nicely packed in thin wooden boxes, each containing two or three pounds of spawn, and also loose in bulk when it is sold by weight or measure.