This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
The time has now arrived when intelligent cultivators are no longer satisfied with a supply of the best fruit during the few weeks when it may be plucked fresh from the tree.
The best artificial method for prolonging the period of maturity must be ascertained; and when once reached, cannot fail to be sought with great eagerness. For it becomes a matter of no little consequence, whether the cultivator, who has expended a considerable sum to purchase, raise, and carefully cultivate a fine orchard of trees, be permitted to eat the best fruit only during two or three months of " the fruit season," or to feast on melting pears, all through a long winter, and till the fresh trusses of strawberries are reddening his garden beds the next summer. This is no chimera - it will be done.
The old fashioned receipt for keeping winter apples, was " to lock them in a cool cellar and hide the key." But this simple process will not answer for pears. These evaporate moisture much more rapidly than apples, which have a more impervious epidermis. Place an apple in a dry room, and it will continue plump for a long time. During the same period, a pear will become badly shrivelled.
Winter apples are usually subjected to many changes before the time comes round for them to be eaten. They are placed in a dry room, tending to evaporate their moisture; there are removed to damp cellars, where moisture is re-absorbed; changes of temperature, besides being accompanied alternately with dryness and humidity, also affect the keeping qualities by the direct action of heat and cold. It is not surprising that pears, when subjected to these changes, being much more susceptible than apples, should be found so hard to keep. This is the reason why we so often hear the complaints, " I can't keep winter pears" - or, " they wont ripen with me, they either wither, or rot, or both" - " winter pears are a humbug!"
I the best Bartletts and Virgalieus could be taken from the tree five days before their usual period of maturity, (as they always should be,*) and submitted to a temperature scarcely above freezing, and where no change, either in temperature or moisture could occur, they would keep an indefinite length of time - it is bard to say how long, - whether seven months or seven years - and the nearer they are made artificially to approach this condition, the longer they will keep. This, with the exclusion of light and moisture, which always tend to produce decay, constitutes all that is at present known and established, relative to the keeping of fruit in a simple unprepared state. The exclusion of air from fruit in its simple ordinary condition, is of less importance than is usually supposed, as it usually contains within itself, all the elements for fermentation.
In constructing a fruit room, therefore, the first and leading requisite is to guard against changes of temperature, that is, to exclude frost and heat. Hence, the same principles substantially must be applied, as in the erection of an ice-house - the adoption of double walls, double roof, and double doors, forming perfect non-conductors of heat.
The annexed plan exhibits, in substance, the best mode at present used for the construction of the walls and shelves. The walls are double, and may be made of brick or of matched boards - the former will be most secure from changes of heat and cold. The enclosed plate of air serves as an additional non-conductor; but as its circulation in this confined space carries the heat from one wall to another, a filling in of some porous substance to prevent this circulation, is a decided improvement. Col. Wilder is very successful with charcoal dust - saw-dust or dried tan would be as efficacious. On each side of the room is a window, a a, corresponding with the two walls, so that the room may always be kept dark; each shutter is made of boards, double, or with a confined portion of air. These windows serve for cleaning and airing the room before gathering the fruit, and for ventilation in a few rare instances, when occupied. The doors., b, are also made double. In ordinary cases, all the ventilation required is effected by registers placed in the walls near the floor and roof. The table, c, at the center of the room, is used for the reception of fruit, before placing on the shelves. It is covered with cotton, or other soft substance, to prevent bruising.
The shelves are divided into narrow strips, with the space of an inch between each, to facilitate the circulation of air through them. The upper ones are raised at the back, as shown in Fig. 2, that the fruit may be easily seen. All are provided with a ledge-board in front.
Marshall P. Wilder, of Boston, has given much attention to the preservation of winter pears, and has been so successful as to keep good specimens through the whole of spring into the summer months. His fruit room was at first below ground, or in other words was a eellar, but he found it too warm, too damp, and not well fitted for the purpose. He then adopted the opposite extreme, and constructed a fruit room over his carriage-house, having double walls, filled with powdered charcoal. The fruit is arranged on shelves, and on the approach of the severest weather of winter, it is removed and packed in boxes, with a thin layer of clean rye straw between each tier. The boxes are then placed together, and covered with hay three feet deep. Joseph Moorman, of London, has a fruit room, also over a carriage house, the walls not filled in, and perhaps in other respects not so secure from frost as would be desirable. A small stove is therefore placed in one corner, to be used when necessity demands. (It is also used for repelling moisture.) He succeeds admirably, however, in preserving an even temperature, and slates that " when the weather becomes frosty, it is several days before the thermometer is affected as much as one degree." The fruit room of the London Horticultural Society, under the charge of Robert Thompson, is doubtless a more perfect structure; the double walls, eight inches apart, are filled in with dry moss, and according to the statement of H. W. Sargent in a former number of the Horticulturist, fire is never used, although the thermometer in open air has sunk to 5° below zero.
The fruit is on open shelves. Long continued severe weather, as often occurs in this country, would of course be more difficult to guard against than a sudden snap.
* There may be a very few exceptions - such, for example, as the Andrews.
It is obvious that artificial heat should be used with extreme caution, as it is changes of temperature and of moisture that cause speedy decay. Ventilation by opening the room to the air outside, is only to be effected when the temperature within and without are the same. Some French horticulturists have made use of the chloride of calcium41 fur absorbing the superabundant moisture of their fruit rooms, which entirely obviates the necessity for currents of external air, and without any change in temperature. It absorbs double its own weight of moisture, and then becomes liquid. It is placed in a shallow wooden box, so as to expose two or three superficial feet to the air, the box being open also at one corner, which being placed lowest upon a table the liquid chloride immediately drains off and runs into an earthern vessel. It may then be dried over a hot fire, and be as good as before.
The amount of moisture in differrent localities and situations, is no doubt quite unlike. Some cellars are much dryer than others, which is a reason that some are quite successful in keeping fruit, when others with equal care entirely fail. An important object in selecting an upper room is not however merely to avoid moisture. To secure coolness is the main reason - especially during the last half of autumn, when a great many winter pears are permanently injured for keeping by too much warmth. But the moisture of the air should be so regulated as never to condense upon the fruit, (kept at the same temperature,) producing what is usually termed sweating - nor to be so little that the fruit shall throw off its juice to the dry atmosphere, producing shrivelling. A little experience in a well constructed room would enable any one to manage this point accurately.
We should have mentioned, when speaking of the construction of the shelves, that they should be evenly covered with some soft substance, one of the best of which is hay made from the spear or June grass, (Poa pratensis,) which is remarkable for its softness and elasticity. The fruit should then, after being carefully assorted from all bruised or decayed specimens, and wiped dry, be placed in a single layer upon this, without touching.
It will be understood by all familiar with keeping winter pears, that when the specimens approach the usual period of maturity, they should be successively removed to a warmer room, where a few days will develope their golden color and their melting texture.
As we have already observed, the great leading requisite is a low and uniform temperature, and exclusion from light; the fruit haying the elements for fermentation within itself, the absence of air is not of great importance, under ordinary circumstances. The great success which has been found to attend packing in charcoal, sawdust, chaff, etc., is largely owing to the preservation of a uniform temperature by these non-conductors of heat, and to the exclusion of light - with occasionally the additional advantage of admitting of being placed in a cold and damp cellar by absorbing the surplus moisture.
* Obtained by heating common chloride of lime.
All this care will, no doubt, appear to some as altogether too great for practice. But even supposing that the room and its management will cost as much as the fruit garden and its cultivation, would not doubling or tripling the period for the maturity of pears, amply repay all trouble? And, estimated by money merely, would not such a room for the marketer of the finest specimens, prove eminently profitable, by enabling him to sell his best specimens for twenty-five cents each, as has been repeatedly done both here and in Europe, for well kept rare sorts? Many thousands could be placed in a single building; and as high profits are in future to accompany the cultivation of the very best, it is well worth while to look at the mode that shall contribute to the highest perfection.
Such a room as we have described would be an admirable place for grapes, either deposited on the shelves, or (still better) suspended by wire hooks at the apex of each bunch, causing the bunches to spread and the grapes to hang apart and prevent rotting.
In all cases where a cellar is used for keeping fruit, as is usually the case with common winter apples, the evils of dampness may be much lessened by placing the shelves in the centre, (a, Fig. 3,) and leaving a space all around for passage. (b. b.) These shelves may be suspended on iron rods, at such a distance from the walls and floor that the most expert rat can never reach them by his longest leap. They may be twice as wide as usual, as they are reached from the passage on both sides.