AN ENCYCLOPAEDIA OF HORTICULTURE. 



399 



Mushrooms continued. 



and should be avoided as much as possible; yet it is 

 difficult to keep the surface sufficiently moist when fire- 

 heat becomes a necessity. Sometimes, when beds hare 

 become very dry, a good watering has caused a heavy 

 crop to spring up ; consequently, it is not always an 

 injurious practice. The walls of the Mushroom house 

 should be frequently syringed, and the floor always kept 

 moist, especially when the use of fire-heat is necessary. 



Outside Culture. Growers of Mushrooms on a large scale 

 for market, pursue a different system altogether from that 

 just described, by forming their beds in ridges outside. 

 These ridges are made on a hard piece of ground, and are 

 about 3ft. wide at the base, the two sides sloping some- 



FIG. 616. PLAN FOR PROTECTING OOTSIDE MUSHROOM BEDS. 



in winter, is shown in Fig. 616. Any sort of frame- 

 work might be roughly constructed above the bed on 



FIG. 615. RIDGE MUSHROOM BED. 



what steeply to the top (see Fig. 615). The manure is 

 collected from stables, and turned a few times, but it does 

 not receive so much preparation as is recommended above 

 for indoor beds. It is well trodden, and the sides are 

 beaten hard into shape. After spawning, the whole surface 

 in covered with about 2in. of adhesive loam, which is 

 ri Dually watered, and then beaten with the back of a 

 spade. A covering of litter or long straw, varying in 

 thickness according to the temperature of the bed, is i 

 kept over the whole, as shown in the illustration, to j 

 ward off storms, and preserve, as near as possible, a 

 uniform temperature underneath. It is obvious that j 

 this system involves a considerable amount of labour i 

 not required with beds inside, in covering and uncover- I 

 ing for every purpose, yet it is practised most success- I 

 fully and very extensively by growers for market, j 

 Another plan, which may be useful for growing Mush- 

 rooms in outside beds, and affording them protection 



FIG. 617. STRAW SCREEN FOR COVERING MUSHROOM BEDS 



rhich to place mats or other coverings, and a cord run 

 over to fasten them on. Straw screens (see Fig. 617), 



Mushrooms continued. 



or thatched hurdles, are excellent movable coverings, and, 

 being non-conducting, they are well suited for preserv- 

 ing an equable temperature, where the admission of light 

 is not necessary. A crop of Mushrooms is frequently 

 found growing naturally outside in places where they 

 are least expected, and such produce is considered 

 superior to that obtained under artificial cultivation. 

 The insertion of some spawn in an old melon bed, in 

 the ordinary turf of a lawn, or in a small quantity of 

 manure in any old cool frame, are also methods, at 

 times, successfully practised with but little trouble in 

 the summer and autumn. 



Preparation of Spawn. What would be more correctly 

 termed mycelium, is usually, in the case of the common 

 Mushroom, called spawn. It is a dense, white, fibrous sub- 

 stance, found in quantity amongst old hotbeds, and in 

 places where cattle are kept, these situations being most 

 suitable for encouraging its growth. A dormant vitality 

 is retained by this spawn for a very long time, if kept 

 quite dry; consequently, the soil or manure containing 

 it may be collected in a loose state, and scattered on beds 

 artificially prepared, at any time. A plan which is, how- 

 ever, preferable to this, and the one most generally 

 adopted, is the preparation of spawn in what are called 

 bricks, from their resemblance in shape to flat bricks. 

 These may be purchased from nurserymen, ready for use, 

 at any season, about sixteen being considered equal to 

 a bushel. Extensive cultivators sometimes prepare their 

 own brick spawn ; but only a very few, compared with 

 the number who purchase it. One of the modes of pre- 

 paration is briefly as follows : Fresh horse -droppings are 

 collected and mixed with cow-dung, some using an equal 

 proportion of each ingredient, and some a less quantity 

 of the former, and a little adhesive loam is added to hold 

 the other constituents together. The whole is mixed 

 with liquid stable manure, until as soft as mortar, when 

 it is spread on the floor of an open shed, until sufficiently 

 dried to form into bricks of the shape and size desired. 

 These should be set on edge, turned frequently, and 

 allowed to get about half-dry. Then a hole, abont lin. 

 square, should be made in one side of the brick, near the 

 centre, and filled with good spawn, inclosing it with a 

 little of a similar substance to that of which the bricks 

 were made. Prepare a bed of fresh horse-dung, about 

 9in. thick, on a dry bottom; build the bricks in a pile 

 above it, allowing a space between each two, and cover 

 with litter, so as to retain a temperature underneath of, 

 as near as possible, 60deg. Under such conditions, the 

 spawn will spread itself throughout the whole of each 

 brick, and the latter must be frequently examined and 

 removed when they are permeated with a white cloudy 

 substance, not so far advanced as to show minute threads. 

 Good bricks of spawn should be in this condition when 

 purchased ; otherwise, any part which is too far ad- 

 vanced, or, on the other hand, not properly permeated 

 with mycelium, will be useless. When removed from 

 the hotbed, the drying process should be completed 

 thoroughly, and the bricks stored in a cool, dry place, 

 to arrest any further vegetation, until required for use. 

 Other systems of preparing brick spawn are practised, 

 differing mainly in details concerning the proportion of 

 the different substances which it is advisable to use in 

 the preparation and formation of the bricks. 



Mushroom Houses. A Mushroom house may either be 

 a span-roofed structure, or one with a lean-to roof against 

 the back of a high wall. It should be situated as much 

 as possible in the shade, in order that the internal tempe- 

 ratures may not be subjected to so much fluctuation, 

 by reason of the sun shining on the roof. Hot-water pipes 

 should be provided for maintaining the proper tempera- 

 ture in winter; but fire-heat is best done without as 

 much as possible. The interior space may be fitted 

 up for beds according to its size and shape, by having 



