The different species of Cyclamen or sow-bread are humble plants, likewise well adapted to the framed border, where they make a very beautiful appearance.
In many gardens, where fine bulbous plants are much attended to, as at the Botanic Garden at Liverpool, all the borders immediately in front of the various hot-houses are covered with moveable frames. In these framed borders, it may be added, many alpine plants may likewise be pre served during winter ; for such plants being accustomed, in their native place of growth, to the protection of a thick covering of snow during that severe season, are impatient of intense cold.
Green-house.
531. The proper situation for the Green-house has been already pointed out (§ 55.) as being somewhere in the flower garden. Its aspect ought of course to be towards the south. In fixing on the plan and elevation of a green house, there is great scope for fancy and taste ; for the in dulgence of these is quite consistent with the production of a house, which shall afford shelter during winter to plants which require little more than to be saved from the effects of frost. It is scarcely ever wished that the temperature should exceed Fahrenheit ; and when the weather is such that air can be given, it is enough if the thermome ter indicate from 38° to 42°. To every part of the house, however, light ought to be freely admitted, else some of the plants will necessarily become drawn up and distorted : a great part of the front of the roof should therefore be of glass. Nicol observes, that a green-house may have two straight sides, but should have circular ends ; he is better pleased, however, with an octagon, whose sides are not equal, but which has two opposite longer sides, forming as it were an " angular oval." In some gardens the green house forms a complete circle; in others it is of an oval shape : in these cases, and indeed in general, it is now con structed of glazed frames on every side. The roof is not made nearly so lofty as formerly ; indeed, it seldom ex ceeds in height fen or twelve feet from the paved walk. The furnace and stock-hole are of course as much con cealed as possible ; and if the house be circular or octa gonal, the smoke is carried by a flue under ground to some distance, and then discharged by a small chimney, hid by shrubbery. The interior is fitted up with stages and
shelves for holding the plants. These are arranged ac cording to their sizes, the shape of the leaves, and the general tint of colour : the smaller plants are chiefly plac ed in front, and those that are likely to flower during win ter have conspicuous stations allotted to them: the taller plants occupy principally the back shelves : in this way a symmetrical mass of varied foliage is presented to the eye, interrupted only by projecting clusters of variously co loured blossoms. Several of the sashes, or perhaps each alternate sash, should be made moveable, for the admis sion of air ; and ventilators are also proper for promot ing a circulation, when the state of the weather prevents the admitting of air by the roof. Very little water is given to the plants during winter ; and they are cleared of dust rather by means of a bellows than by the applica tion of the syringe.
The roots of green-house plants are generally examined twice in the year, by turning the plants gently out of the pots. Many kinds only need repotting once in the year ; and this operation is commonly performed in August : but others require it twice in the year, and the other period is usually March. It is not always necessary that the plants should be shifted into larger pots; on the contrary, it is often better to retrench the matted roots, and keep to pots of the same size. It is always proper that some small gravel or shivers of broken flower-pots be put in the bot tom of the pots, to drain off moisture. And here a very common error in the manufacture of that earthen-ware article may be pointed out : the hole in the bottom is frequently made so as to have a small unintended rim on the inside, which necessarily retains a portion of water ; whereas the sides of the hole ought to have a slope from the interior, so as to allow every particle of water to escape.