Within the last twenty years there has been a great advance made in the successful cultivation of the Pine-apple; and although that may be attributed, in a considerable degree, to the improvement in the structures for its growth, and in the methods of commanding the desired temperature, yet probably the advanced state of the knowledge of the laws and principles of vegetable life which has been acquired by practical men has done still more than the improvements in the appliances that they now have to work with.

As we all know, the Pine-apple is a tropical fruit. The general principles by which the growth of it is governed must be constantly borne in mind; and with a due attention to such of these as are consequent more or less upon its native habitat, the intelligent gardener will find little difficulty in adapting his practical skill to the production of fine specimens of the noble fruit.

The general principles alluded to in the preceding paragraph are chiefly the following: The range of temperature required is from 60° (Fahrenheit) to 90°, with the means of commanding bottom heat (to an equal extent, or nearly so,) in the soil in which the plants grow, or in the material in which the pots containing them are plunged when they are not grown in the soil without pots. When growing vigorously, a considerable degree of moisture is required; more in the atmosphere than at the root, although the soil, at such time, requires to be kept in a damp condition, but so as never to remain saturated. Air must be supplied liberally when heat and light are abundant, to prevent the plants becoming drawn. A rapid growth, provided this is attended to, will always produce the finest fruit. At all times when the external temperature is low, the growth should not be so rapidly pressed forward, (especially that of the young stock,) but at the same time care must be taken not to produce a sudden check by too great a reduction of heat.

Having stated these general principles of cultivation, we will now give some account of the different modes that are adopted to obtain the requisite conditions of growth as regards plant structures, and modes of heating, and afterwards we will make some practical suggestions for the management of them.

The most simple but by no means the best structure for the growth of Pines is the Brick Pit, the heat being obtained from some fermenting material, such as stable manure, tan, or decayed leaves. When this is adopted, there should be an outer pit surrounding, or on three sides of, the inner one, to admit of the renewal by linings of the fermenting material from time to time, to keep up the heat.

An improvement upon the above pit is to run a brick flue through it, by which the heat can be much better insured; and by such means good fruit may be grown.

Still a better pit can be built by introducing a pipe for hot water with a return pipe beneath the soil, where it must be surrounded with broken bricks, or inclosed within a chamber or flue containing holes to admit the warmth to escape into the soil. By this means, in a pit not more than from twenty-five to thirty-five feet in length, a four-inch pipe will be found a very efficient agent; and we give the preference to such a combined arrangement of fire heat with that from some fermenting material, to that of either of them alone. The reason is this: It has been found by some of the most experienced pine-growers, that where fermenting materials are used a degree of luxuriance has been attained that could only (when compared with other modes of culture) be ascribed to the benefit derived in the shape of nourishment from the ammoniacal, and perhaps other gaseous products of fermentation, when introduced into and converted to its use by the soil in which the plants grow.

The most complete arrangement, at least one that is usually so considered, for a pinery, is, however, a span-roofed house, standing north and south. A narrow path runs round the house. The entire centre is then formed into a brick chamber some two feet deep, into which a hot water tank is introduced; and upon and above this chamber the bed of soil is placed to receive the plants, there being provision made for regulating the introduction of the heat through a stratum of rubble and gravel to the soil above; and for cutting it off altogether. Other pipes introduce the heated air from the chamber below into the house; or sometimes this is effected by a distinct set of hot water pipes.

This is a very effective structure in the hands of an efficient man, but the first cost, if well done, is considerable, and it is more liable to mismanagement than some of the more simple arrangements before adverted to.

Whatever method is adopted, good ventilation, at both top and bottom, should be provided for, and the heating apparatus so arranged that the external air may pass over it and become warmed sufficiently to prevent injury from a chill on its introduction into the house.

The side lights of a house should be so near the ground that the plants may stand on a level with and not below them. And as regards heat, the artificial means employed should be adequate to the supply of it, so as to command from 80° to 90° if needed, whatever may be the time of year.

We proceed to add some hints on culture.

Pine plants are raised from the crowns of the fruit, or from offsets or suckers produced by the stem. These, when taken off, should lie in a dry room for two or three days to harden, a few of the bottom leaves being first removed. These may be planted in a hotbed, or first potted each in a small pot three or four inches in diameter. The soil must be firmly pressed round them, and then let the pots be plunged in a hotbed, and shaded from the hot sun until well rooted. A little water will be required at root, and the tops should be surrounded by a moist atmosphere, which may be obtained by-sprinkling them slightly. When the pot fills with roots, shift into a larger pot without breaking the ball of roots, and plunge them again in the bed.

The soil for Pines is a turfy loam not too heavy, chopped up with a spade, and used in a rough state, and not sifted. Some bone dust or broken bones may be added; and a small quantity of decayed leaves or leaf mould will be of advantage, if the loam is stiff.

When the plants have been shifted once out of their striking pots, those that have made good roots to fill the pots may be grown rapidly through the summer and fall months, increasing the supply of moisture and air, according to the heat, and shifting as required by the degree of the root growth, until they are got into their fruiting pots, which may be not less than ten or twelve inches in diameter. It is undoubtedly best to plunge the pot up to the rim, or nearly so, during the whole time of growth, as it is much easier to maintain the temperature at the desired point by so doing.

In shifting the plants examine the roots, and disentangle or loosen slightly the points of some from the ball, so that they may readily take hold of the new soil when shifted; but avoid breaking or cutting away any except a decayed root. It is best to avoid shifting plants from October to February in localities where the external temperature is severe in winter. During those months light is deficient, and the aim then should be (by keeping the plants at a temperature not less than 60° to 65° at night to 75° in day) to prevent them from sustaining any check, but not to stimulate growth, until the approach of spring and summer affords the expectation of congenial temperature to aid the exertions of the gardener.

The system of planting out the Pines in the house instead of fruiting them in pots is now much more popular with pine-growers than it formerly was; and provided the arrangement is good for the supply of bottom heat, it doubtless has many advantages; and it also saves labor. Without adopting the tank system referred to above, the bed for the plants may be prepared by covering the bottom with a layer, well rammed down, of stones, broken bricks, and rough gravel, some six or eight inches deep. On this lay hot water pipes, covering them over with the same material, and then a layer of turf over the whole; upon this place the soil for the -plants about twelve inches deep. The soil should consist of the turfy loam before mentioned, rough, and rather larger bones (broken the size of walnuts) than for pot culture.

After planting keep the house shaded a few days, and rather moist and close. Give air liberally in fine, bright weather, and water sufficient to keep the soil damp, but not saturated. The atmosphere should be kept always moist (except in severe weather) by sprinkling the plants, (but not so as to cause water to remain standing in the axils of the leaves,) and by throwing water on the paths. Give air liberally whenever the external temperature allows, and shade slightly in very hot weather. Never let the temperature sink below 58° to 60°. With favorable weather and a rapid growth in progress, it may advance to 90°, or even higher. More water at root will be required as the fruiting plants swell to maturity, but when full grown slightly reduce the moisture at top and bottom, by which means the ripening process will be more complete and the flavor enhanced.

The same rules of general management apply equally to the plants in pots.

[At this time, when pineries are occupying no inconsiderable share of attention, the above interesting article by an old pine-grower will prove highly acceptable. We have the promise of more on the same subject There are already four pineries in the vicinity of New York, and more under way. - Ed].