400 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



[ June 2, 1863. 



may perhaps come up plain green. Arototis grandiflora may be 

 sown at the same time as Gazania, to -which it bears some resem- 

 blance. The Centaurea argentea, or C. candidissima, might be 

 sown at once, as the plants by being kept in pots do not grow 

 fast ; and, if they do so, cuttings from them will be useful. If 

 you have not the convenience of a hotbed in which to forward 

 the above plants nest spring, but have a cool greenhouse or some 

 pit where they can be secured from frost, it would be better to 

 take cuttings of all of the kinds in August, and keep them in 

 store-pots until March or April, when they may be potted-off, 

 and wiil make good plants before planting-out time. — J. R. 



GEOWING MUSHEOOMS IN POTS. 



Mr experience in this mode of culture is by no means 

 extensive, having only tried the system once, and that several 

 years since. It proved perfectly successful ; and some of your 

 readers may feel inclined to ask this question — viz., Why not 

 continue to practise it ? My answer is simply the same as with 

 regard to fruit, They can be obtained equally good, and with 

 less trouble grown in beds in the usual way. 



But for the benefit of any of your readers who may "feel 

 interested in the subject, I will detail my practice as correctly as 

 I can. Early in the month of November, some years since, I 

 found that it was desirable that I should produce Mushrooms 

 as soon as possible. I had an excellent Mushroom-house 

 under my care, but I had not a sufficiency of the material to 

 make a bed — viz., horse-droppings. I, however, made a slight 

 hotbed in the Mushroom-house, composed of half-rotten leaves, 

 sweepings of lawns, &c. ; and at the same time I carefully 

 collected what droppings 1 could, so that by the time that the 

 temperature of the hotbed had declined to about 80°, I had 

 enough of droppings to £11 three or four dozen nine-inch pots to 

 withm an inch of the top. These pots I at once plunged nearly 

 to the rim in the hotbed ; and when I found that the material in- 

 side the pots maintained a temperature of about 75° or SO, I in- 

 serted a piece of spawn as large as a hen's egg in the centre of each 

 pot, making all very firm, and covering the surface of the pots 

 with about an inch of stiff soil made quite damp. No water 

 was ever given. In about three weeks the temperature of the 

 hotbed had somewhat declined ; the pots were then removed, a 

 little fermenting material added to the bed, turning it at the 

 same time, and immediately replunging the pots.» 



The temperature of the bed was never allowed to fall lower 

 than 75° ; and m rather less than six weeks from the day the 

 pots were spawned, the surface of every pot was covered with 

 small Mushrooms, which rapidly increased in size. As the at- 

 mospheric temperature of the house was kept to about 60°, on 

 account of Sea-kale, Rhubarb, &c, being also forced there at the 

 same time, this temperature brought the Mushrooms on faster 

 than they were required. So they (the pots), were removed 

 into a cool, dark, root-cellar, where they continued to produce 

 excellent Mushrooms for some considerable time ; in fact until a 

 subsequently-formed bed could keep up the necessary supply 



HEATING GAEDEN STEtJCTUEES. 



Thebe are few subjects of greater importance to the gardener 

 than the proper erection of those edifices known as stoves and 

 greenhouses. 



Site or aspect is the first consideration. A site overshadowed 

 by trees is unsuitable for fruits, though it may do very well for 

 plants that delight in shade ; yet even open sites are not always 

 the best for the erection of houses for the successful cultivation 

 of fruits. A site may be open but still bleak, and that materially 

 affects the heating of the house and the giving of air. A shel- 

 tered situation is an essential in a climate like ours, and has 

 more to do with the economical heating of houses than is gene- 

 rally imagined. 



Suppose a house to be erected in a bleak place without shelter 

 of any kind, and another to be put up in a sheltered situation. 

 They are both heated alike, but the fire of one has to be kept going 

 on a cold windy but sunny day, whilst that in the sheltered situa- 

 tion is warm enough without the application of fire heat. The 

 one has the cold air driven against its sides, cooling the internal 

 atmosphere faster than the sun's rays can heat it ; but from the 

 other, sheltered from the wind, little heat is abstracted by the 



Vet a house may be cold irrespective of site. A house in a 

 sheltered place with the laps of the glaBs open will be as cold 

 as a house in a bleak situation with the laps puttied-up. Then a 

 lean-to house requires lesB heating than a span-roofed one. There 

 is a loss in the latter of nearly one half of the sun's rays by 

 reflection by the construction of the roof alone, to say nothing 

 of its presenting a larger amount of surface to the cooling action 

 of the surrounding atmosphere. A lean-to at an angle of 45° 

 loses little from reflection in summer, but in winter nearly half 

 the sun's rays are reflected: consequently a lean-to covering 

 300 square feet enclosing 2400 cubic feet of air requiring the 

 temperature to be kept at 60°, will require 80 feet of four-inch 

 hot- water pipe at a temperature of 212° ; but a span-roofed house 

 enclosing the same amount of air will require 60 feet more to 

 obtain the same result. 



I am not speaking of lean-to's and spans in their relative 

 situations as regards light ; I do not wish to maintain that lean- 

 to houses are more suited to vegetation than a span-roofed, but 

 to show that a quantity of enclosed air is more rapidly heated 

 and more economically in the former than in the latter. 



The size of the house also has a good deal to do with the 

 heating. A small house proportionately requires more heated 

 surface to heat it than a larger. The former presents a corre- 

 spondingly greater amount ot radiating surface to the surround- 

 ing air than the latter, and, as is well known, becomes sooner 

 cold. A house 50 feet long by 20 will require 280 feet of four- 

 inch pipe to maintain a temperature of 60°, and a house of the 

 same length, but only 12 feet wide, will require the same amount 

 of piping. The space in the latter will certainly be heated 

 sooner to a given temperature than the larger house ; but it will 

 lose more by radiation and be cooled, in the same manner as 

 it became warm, more quickly than the large house. 



The heating of houses is also affected by moisture. Very 

 moist atmospheres require a larger amount of heated surface to 

 secure the same temperature in them than those several degrees 

 drier. Our ferneries and Orchid-houses afford examples of this. 

 I have noticed that a house in which a hygrometer denoted 

 95° of moisture (Saturation = 100) took nearly half a-day 

 (5h. 45m.) longer to secure a temperature of 85° than a house 

 with the same amount of heating surface where a hygrometer 

 indicated 67° of moisture; and in cooling down the moist 

 atmosphere was 4h. 57m. longer than the dry atmosphere. 



Another point of no small import in the heating of houses is 

 ventilation. It is necessary to provide for the admission of 

 fresh air and the egress of foul. Stagnant air is inimical to 

 healthy development in vegetation, and as the admission of fresh 

 air is calculated to lower the internal temperature, provision 

 must be made to prevent its doing so. The presence of the sun 

 is the old-fashioned signal to give air ; but as the sky is liable 

 to be overcast for weeks, the atmosphere of our houses must 

 be stagnant enough if no air be given during the sun's 

 absence. It is not false economy to provide for a change of 

 atmosphere at least once in twenty-four hours under all circum- 

 stances of cold and wet ; and it is also necessary to provide for 

 a fluctuation of temperature, or a rise of 10° or more above the 

 calculated amount of temperature the heating apparatus is ex- 

 pected to secure. 



Ventilation when it lowers the temperature denotes a badly- 

 constructed heating apparatus. Many gardeners are prevented 

 giving air through the deficiency in the apparatus, which maybe 

 theoretically properly constructed, and calculated to serve the pur- 

 pose for which it was intended ; but from the builder's ignorance 

 of the smaller matters we have pointed out he makes a sorry affair 

 of an otherwise good one, and often throws the plants into diseases 

 which are attributed to the gardener. A few additional feet of 

 heating surface is a good excess ; in fact, a necessary help to 

 successfully grappling with the vicissitudes of a fickle climate. 

 There are only three ways of heating houses : by fermentation, 

 hot water, and hot air. The first is spontaneous, therefore more 

 Buited to vegetation than any other heat (solar heat excepted). 

 It is ea3y of application, and satisfactory in its effects ; but its 

 utility is materially impaired by the frequency of the necessity 

 to renew it and the constant care necessary to secure the proper 

 heat. Formerly dung was pre-eminently the best material for hot- 

 beds, and it is now the best — at least, the most conducive to 

 vigorous growth — for forwarding and maturing the fruits of 

 plants of short duration. It has also the advantage of main- 

 taining a steady bottom heat ; but it cannot be made to raise 

 the internal temperature 10°, without solar heat, in a few hours, 

 on the occurrence of a very frosty night, neither is it easy to 



