A conservatory is, properly speaking, a house in which plants which have been brought to perfection in a greenhouse are displayed ; but often the house will be used to some extent for growing them as well.
The Conservatory as a Show House
Like a greenhouse, it may be an adjunct to the dwelling-house - indeed, it usually is such - and even when small it forms a pleasant extension to the drawing-room. The essentials of the structure are the same as for greenhouses - namely, that it should be strong and well built, standing on dry ground, and having ample means of ventilation. The aspect should be southerly, if possible, and sheltered from cold winds. In having a greenhouse or conservatory built, the bond, as the arrangement of bricks is called, should be a good one, half-bricks not being joined in too large a proportion. Probably the English bond is best.
Any ornamentation used on the house should be as restrained as possible, since it is apt to interfere with the objects of construction - namely, to provide a light and airy building for the culture of plants.
As in the case of greenhouses, the best arrangement for heating, because the cleanliest and most equal in temperature, is that of hot-water pipes, a well-set boiler being put in with a flow and return pipe on the simplest principles.
A conservatory, broadly speaking, differs from a greenhouse in having some at least of the plants put into beds instead of standing in pots. This arrangement gives an element of permanency to its decoration, while at the same time other plants in pots are renewed as they come in and out of flower.
Among the former class may be planted camellias, roses, abutilons, many acacias, cassia corymbosa, the boronia family, cytisus everestianus, hydrangeas, eriostemon buxifolius, luculia gratissima (a handsome and very fragrant rose-coloured climber), African hemp, Grevillia robusta (a handsome, fern-like plant), plumbago capensis planted against a wall, bottle-brush myrtle, sta-phelias, linum tigrinum, jasminum grandi-florum, oleanders, magnolia, and other shrubs for permanent effect. It is a great pity that pomegranates are not more often grown, whether as small or large pot-plants, as they are in Germany.
Plants to Make a Good Show
Climbing roses, Passion flower, allamanda, heliotrope, and so on, are almost always planted against the back wall as a matter of course, and most people whose conservatory is warm enough should have a bougainvillea, which, when spurred back hard, will break out and make a brilliant show.
Among the other class - i.e., temporary pot-plants, a race of very showy plants are the kalosanthes, cuttings of the young shoots of which should be put in in sandy soil in spring and summer in the greenhouse, and the cuttings potted off singly when rooted. The cuttings, if properly pinched back to form a base, will become nice bushes in course of time. Cuttings rooted in spring, and wintered on a shelf near the glass, should flower freely the following spring and summer. Several plants may be flowered in one pot if a quick result is desired.
The Eastern richardias are, of course, good conservatory plants ; these are best planted out of doors in a rich soil about May, watering the plants copiously in dry weather, lifting and repotting them in autumn, and growing on for winter decoration.
Eupatorium odoratum and E. riparium can be put out at the end of May and treated like the above ; also stevias for autumn and early winter decoration. Salvias may be treated in the same way, though the outdoor stage is not essential.
Basket plants must certainly find a place in the conservatory. These are seen to perfection in the Temperate House at Kew Gardens, where begonias, Cape cowslips, and other flowering subjects, are a joy to the beholder, and are replaced by other seasonable plants as the year goes on.
Some of the hardier orchids can be grown in this way. The baskets often look well if packed with moss and panicum variegatum to start with. Asparagus sprengeri and such ferns as the well-known " fishmonger's fern " are common yet attractive basket plants.
Very many hardy garden flowers will bear heat, and can be brought on gently for conservatory decoration in early spring. The crimson borage can be pushed in to flower in this way, while Solomon's Seal has a splendid effect if plunged out of doors and then potted up. Early sown Canterbury bells and wallflowers should be used also; these and similar subjects are the amateur's stand-by when only wishing to make use of one house. Where facilities can be had for forcing plants and shrubs into bloom, there need, of course, never be a scarcity of colour in the conservatory.
For cases where the conservatory is without any heat at all, a list of suggested plants will be valuable. Foliage subjects will include palms, aralias, dracaenas, bamboos, aspidistras, the Norfolk Island pine, and so on ; while among flowering subjects one can grow all sorts of early bulbs, first plunging them under ashes out of doors, also the bleeding heart, and spiraeas, irises, maiden's wreath, Christmas roses, and early flowering chrysanthemums. Myrtles make a nice show, shrubby veronicas also; while such decorative subjects as Japanese lilies, Scarborough lily, perpetual-flowering carnations, coronilla glauca, aralia sieboldii, azalea indica, and arundo donax are other plants chosen at random which will make the small conservatory bright throughout the seasons.
The shrubby veronicas should be planted in borders in the house, as they dislike to be restricted in root room. Treated thus, they will give a beautiful mass of pale mauve spikes in April and May. Shrubby calceolarias are also pretty, and one of them, the calceolaria violacea, is not so well known as it should be for conservatory decoration.