The Amateur's Greenhouse and Conservatory/Chapter 1
Jump to navigation Jump to search
THE CONSTRUCTION OF THE PLANT HOUSE.
Before we begin to construct, we must determine on the site. Now, a bold beginning may be made by the assertion that any site will suit for a plant house, provided the owner will furnish it with plants adapted to the site, and resolve never to make selections without first considering the suitability of the house for their protection. Suppose we have a high damp wall facing north, and wish to cover in the space in front of it with glass for plant-growing. It may be a prudent proceeding to erect there a substantial lean-to, and to construct against the face of the wall inside the house a rockery, and plant the rockery with ferns, and make a lovely scene rich in botanical interest. Or suppose the wall faces south and the position is particularly dry and hot, we may still proceed to cover the space in front with a lean-to, and make a border next the wall for climbers that love sun and a stage in front for a collection of succulents, which never flourish so well as in a “roasting situation.” Or we may plant vines outside and train them up the rafters, and winter all the bedding plants on stages or beds of earth supported by brickwork in the centre. The question of accessibility is of the utmost importance. You will not care to walk far through wind and rain, perhaps, to see the first flowers of the primulas and hyacinths, or to cull bouquets for the friends who will visit you on New Year’s day; nor on a night of keen frost and falling snow will you benefit your health by walking long journeys to stir up the fading fire on which the lives of your pets depend. Think of these things in time, and if your own health does not enter into the question, be not quite oblivious of the health of the gardener. Not only is the position of the house important, but that also of the stoke-hole and furnace, if artificial heat is employed. Where it is possible to place the furnace under cover and in close proximity to a yard where the fuel is stored, the worst of the winter work will be greatly facilitated, and the owner’s purse will be saved. A furnace under cover will afford more heat for your consumption of fuel than one exposed to the wintry blast, and the gardener will not so much dread the task of stoking on a bitter winter night as he will be likely to do in the case where the glare of the fire and the blinding snow assail his eyes at the same time, and his fingers are frozen at the very moment that his face is flushed with looking into the disposition of the burning fuel.
In the construction of a plant house the first matter of importance is to determine the purpose to which it is to be applied. On this will depend the choice of site and aspect, the size of the house, and the extent to which embellishments are to be employed within and without. It will be well for those who study economy to remember that a very plain substantial house, thoroughly adapted for plant culture, will always look respectable, even if it is not decorated like a pavilion or pagoda; and its use will justify it far more satisfactorily than any amount of ornament. There are some grand conservatories in the land in which nothing of a vegetable nature except mildew will thrive, and not a few very humble greenhouses in which plants grow as if by magic, and provide their owners with an endless variety of priceless (though costless) pleasures. The idle man who does not intend to do much in the gardening way may be wise to build himself a roomy and thoroughly substantial conservatory, attached to or very near his dwelling, and furnish it with dracænas, yuccas, agaves, and dasylirions. An ambitious amateur may set his mind upon a block of houses for camellias, heaths, cacti, pelargoniums, and fifty other classes of plants. This one would do well to consult a garden architect, and determine from the first to do the thing well or not at all. But for every one who requires to be accommodated in a peculiar way there will be hundreds who want what is commonly understood as a greenhouse, and the question is. How are they to begin?
A good general advice to all such would be to erect for the present one good span-roofed house, running north and south, in a quite open sunny spot, and have it as large as the purse will allow for the whole thing to be done properly. A large body of air maintains an equable temperature with far less trouble of management than a small body, and hence in a burst of unseasonable heat in spring, or a sudden accession of intense frost in winter, the plants in a large house will be likely to suffer less than plants of the same kinds in a small house, both receiving equal care and attention. By the term “large house” is not to be understood anything extravagant, but a fair roomy structure, with as low a roof as is consistent with the comfort of the cultivator and the size of the plants to be kept in it. If you employ an architect or builder not practically versed in the construction of plant houses to carry out your wishes, you will probably obtain for an extravagant outlay a heavy structure with a lofty roof, in which nothing worth having can be persuaded to grow. Keep the roof down to something like the actual requirements of the plants, for the nearer they are to the glass the better. The lofty roof is one of the most dangerous delusions the beginner in gardening has to guard against when the question arises about the employment of glass.
It must be repeated that the purpose is the matter of first importance. Heaths, geraniums, and camellias will not submit to the same routine of treatment the whole year round, and at the end of that time present equal indications of health and vigour. The heaths and other “hard-wooded” plants usually associated with them require abundance of light and air, and very little warmth in winter. The camellias are not benefited by such a blaze of light or free current of air as the heaths require. The geraniums require more warmth in winter than either, and all the light they can have, with the ventilation so modified that they suffer nothing from the keen winds and freezing showers of early spring. Now, the amateur may be inclined to ask if every class of plants is to have a house to itself? the answer is, No. In a well-built span-roofed house with brick sides, low roof, ample ventilation, and a sufficient service of hot-water pipes, a very miscellaneous assemblage of plants, including some that properly belong to the stove, may be grown by one who has acquired a little experience. But if the amateur has a particular object in view—such, for instance, as to excel in the production of oranges, exotic ferns, the smaller succulents, &c., &c.—then he must provide accommodation in accordance with the requirements of his special pets, and the odd things must take their chance with the help of such little aids as can always be rendered amid adverse circumstances.
Premising that a well-built house of small dimensions is to be preferred to a badly-built house of great extent, it may be well to suggest that it is a very easy matter to lengthen a house, but a rather difficult matter to increase its width. Therefore let the house be wide enough in the first instance, as you may increase its length to any extent that your land and purse will allow. It is well also to select, if possible, a site adapted for a range of houses, should it be some day hence determined to increase the area of glass. We never know what our desires and intentions may be to-morrow or the day after next, and therefore, though it may seem at this moment that the greenhouse in course of erection will suffice for the rest of our lives, we may in a year or so propose to build another, and perhaps yet another, and be compelled to plant them in all sorts of odd corners, where they will be difficult to get at, and, perhaps, impossible to heat them all with one boiler. A systematic and conveniently arranged group of substantial plant houses, however plain and unpretending, are a credit to any garden, but houses of all shapes and sizes, flung all over the place, as if sown by the tempest, are not creditable, and it will be a wonderful thing indeed if they do not prove to be as inefficient as they are inconvenient. A greenhouse in a corner may be snug and useful, but for superior plant-growing there is nothing like a roomy and airy space on a dry subsoil, or, if the situation is low and damp, on a raised and well-drained platform.
The span-roofed house with low pitch of roof is to be preferred for all general purposes; but the lean-to is not to be despised. One advantage of the lean-to is that it turns to good account the shelter and warmth of an existing wall, and in proportion to the covered area is cheaper than a span. It is not an easy matter to grow perfect specimen plants in a lean-to roofed house, and it is not always possible to ventilate such a house with equal ease and efficiency as a span of the same area. But what we lose in one way we gain in another; and a lean-to with long rafters resting on a high and stout wall, with a south aspect, may be made much of as a vinery, and produce first-rate grapes, without the expenditure of so much as a farthing in seven years on artificial heat. The best house we have ever had for substantial work of the useful kind—for keeping and propagating bedders, for the production of grapes and cucumbers, for safe keeping of a number of stove-plants, and for growing tomatoes and melons—was a lean-to with a low roof and walk sunk below the level, the back wall of which was built of old floor-boards placed double, and filled in between with sawdust.
A number of minor improvements have been adopted of late years in the construction of plant houses, the effect of which has been to cheapen them considerably, without impairing, and in some instances actually improving, their efficiency. We say nothing now of patented ventilators and such like, for it occurs to us to mention, first of all, that heavy rafters and sliding lights have become almost obsolete. It is found that side ventilators are in many instances sufficient; but where roof ventilation is required in addition it may be obtained in a much cheaper and more simple way than by the adoption of sliding sashes. Separate squares of glass may be hung on hinges, or narrow-hinged lights may be inserted at intervals. The disuse of heavy rafters, in consequence of their being no longer required to carry sliding lights, allows of the use, throughout, of light sash-bars, carrying larger glass than was ever used for the purpose until within the past few years. Thus a more complete flood of light is obtained than was possible in the old-fashioned houses, while the ventilation is more perfect and far less cumbrous. As for the glass, it should be good English, weighing twenty-one ounces to the square foot. The low-priced Belgian glass is quite unfit for a plant house, however well it may be adapted for sheds and workshops; its numerous specks and bubbles act as burning glasses on the leaves beneath them, and the result is brown spots, holes, and other disfigurements.
There will still arise, perhaps, in the mind of the amateur a number of questions as to the particulars of the construction of the house required. The proper angle of the roof may be one of them, and that is by no means a matter of trifling import. For all general purposes the flatter the roof the better, because it will conduce to the short healthy growth of the plants, if they are placed as near the glass as possible; but there are two serious objections to the adoption of a low angle. It incurs a liability to drip, and it provides a playground for cats in a district where those interesting quadrupeds abound. We once suffered in a frightful manner through the breaking of a pane of glass on a low-roofed house when a party of cats were holding an out-door nocturnal demonstration upon it. They fell in and went mad with fright, and committed such havoc as for the time nearly broke our heart. The amateur in town must protect his interests, if his plant houses have low-angled roofs, by covering them at the distance of a foot from the glass with a “cat proof” wire-net, or adorning the woodwork everywhere with a miniature chevaux de frise. It must be repeated that for general purposes the flatter the roof the better, especially for mixed collections and bedding plants. But if it is requisite to catch the earliest rays of the morning sun in the opening spring, a lean-to with a south-east aspectand a steep pitch is to be preferred. Therefore, in building an early vinery a nearly flat roof is of all things to be avoided. In any case, if “doctors disagree,” and the angle of the intended roof becomes a question dangerous to anybody’s peace of mind, it may be settled safely by the figure 45, for that is the angle which affords the best compromise, and most safely subserves a number of purposes.
“Tom, away; mark the high noises.”—King Lear.
In fitting the interior we begin with a good paving of red foot-tiles, or something equally good and cheap obtainable in the locality. With mosaic and other fanciful pavements we have nothing to do, for the simple reason that they are costly. There is nothing so good for a stage in summer as large slates, and nothing so good in winter as open wood-work. The houses in which we keep miscellaneous plants have slate stages on each side the centre walk. When affairs are made up for the winter a substantial wood trellis is laid over the slates at afew inches distance, to allow of a free circulation of air around and under the pots. The trellis is made in convenient lengths and consists of deal bars two and a half inches wide, three quarters of an inch thick, set one inch apart, with cross-bars to brace them together. In any case the staging must be so arranged as to bring the plants as near as possible to the glass. The subjoined diagrams represent a good and a bad way of fixing the staging.
“Unheedful, desperate, wild adventure.”—1 Hen. VI.
In fig. 1 is represented one side of a low-roofed span (A), and flat staging near the glass (B). This is a good arrangement. In fig. 2 is represented one side of a steep-roofed span (A), and rising stage (B). This is a very bad arrangement. The central path being in the line A B, the plants are very conveniently placed both for seeing and getting at them, but the lowest are so far from the glass that they must be drawn and blanched and miserable.
The question of material is one of comparatively small importance, because houses of equal value as regards plant production may be secured in either iron or wood, and with either brick or stone or concrete walls. But of necessity there may arise occasions for particular care as to selection of materials, and a few remarks on this part of the subject will be appropriate in this place. To begin with:—at ground line, the question arises, shall we have walls or glass only from head to foot? The Paxtonian houses consist of lights resting in a wooden trough which catches and carries away the rain water, and the thrust of the rafters is received by “chairs” or rests of wood which lodge on blocks of concrete or stone sunk in the ground. Between walls of brick and wood the difference is all in favour of the former as to protective power and duration, but in favour of the latter as to lowness of first cost. As to rafters, those of wood are more perishable than iron, and admit less light. On the other hand, wood is a non-conducting substance, and if a nice comparison were made it would be found that a house with a light iron roof would cost rather more for fuel than a house of the same shape and dimensions with wood rafters, to maintain an equal temperature throughout the winter. But light is life, and iron roofs are adapted to catch the utmost glimmer of the weak daylight of this cloudy clime, and in the case of a structure intended for succulent plants, and such other subjects as need the fullest possible flood of light, iron is certainly to be preferred. In the case of a large conservatory iron is unquestionably superior to wood, and the more so with every advance in elegance of construction.