Diploma of the Royal Botanic Society

Greenhouse Construction - Stagings-the Heating Question - A Spring Start - How to Repot

Plants - General Management

Many town and suburban houses are provided with a greenhouse at the time of building; this is most often a lean-to structure - i.e., a house of which the third side is formed by the house wall. A lean-to is superior to a span-roof greenhouse in keeping out the cold, but a span-roofed house affords more light, and will, of course, accommodate more plants.

The wall of a lean-to greenhouse, however, is a great asset, as it can be clothed with delightful creepers, such as a Marechal Niel rose, a fan-trained climbling pelargonium, a camellia, cherry-pie, lemon-scented verbena, passion flower, or some suitable fruit tree such as a fig.

Building- Construction

The wails of a glasshouse are best formed of bricks, ventilators being arranged by leaving a brick out here and there, covered with a slip of wood which can be made to slide backwards and forwards. The panes used should always be of 21-ounce glass, free from flaws, and must be set in good putty, or fixed by one of the patent methods now in vogue. A groove should always be cut in the rafter, or some other form of gutter must be provided, to prevent drip. In a structure measuring 20 ft. by 12 ft., a good average for the slope of the roof would be an angle of 370. The top and side ventilators should open and close easily. If possible, the greenhouse should have a southerly aspect.

Man or small span roof greenhouse in which space is used to the best advantage. Aa. Central Staging (tiered); Bb. Side Benches ; CC. End elevation of planking for standing seed boxes and pans ; Dd. Hanging Baskets ; Ee. Hot water pipes ;

Man or small span-roof greenhouse in which space is used to the best advantage. Aa. Central Staging (tiered); Bb. Side Benches ; CC. End elevation of planking for standing seed boxes and pans ; Dd. Hanging Baskets ; Ee. Hot-water pipes ;

Ff. Ferns and Staging

The pathway of a greenhouse may be either of concrete, gravel, ashes, tile, or any other clean and well drained substance. Wooden trellising may be laid over a floor of earth or ashes, the strips being nailed to cross-pieces placed at intervals of 4 ft. or 5 ft., and this makes a suitable pathway, beneath which selaginallas and other creeping plants will thrive, peeping up here and there between the woodwork.

The Water Supply

Proper provision should be made for a good-sized tank to hold soft water, to be saved from the roof. Such a tank should be made of bricks built in with cement, and covered with a thick coating of cement afterwards - unless it is decided to adopt the more impromptu method of fitting a large cask in the corner of the greenhouse, tarring it inside and painting it outside.

Greenhouse stagings - i.e., the shelf accommodation on which the plants are arranged - may be of different materials. Trellising is the most usual form - i.e., that in which horizontal pieces of wood are fixed, with spaces between, allowing the superfluous moisture to pass away freely when the plants are watered. Other forms of staging are solid, when the plants rest on a thick layer of coal ashes placed upon the bench, or of shale, etc. Shell gravel is a very suitable medium.

Wooden staging will be arranged either flat or in tiers, according to taste and convenience. The painting of the woodwork will be found an enjoyable occupation, but it must be remembered that the back and sides of all the wood must be painted as well as those portions which are seen, the great object of painting being to preserve the wood. The best white lead paint should be used, and two coats be given, preceding the first by priming - i.e., putting on a coat of mixed red and white lead paint. " Japanol" is a preparation of enamel paint which, though expensive, keeps in preservation for a longer period than ordinary paint.

The Heating Question

Heating will usually be done with a good stove, but if oil or gas must be used, the. apparatus should be placed outside, or the appliance at least possess pipes for the escape of the fumes, which otherwise would be injurious.

Where - and this is the best plan - a boiler is used, the upright form will probaby be the most convenient, and if properly stoked it will keep up the heat for many hours. For an upright boiler coke should be used. In the saddle form of boiler anthracite coke or coal may be used; but when anthracite is employed, some ordinary coal must be added when the fire is started, because anthracite is too hard to ignite by itself.

The flues of an upright boiler should be cleaned at least once a fortnight.

Four-inch pipes will generally be used, and these should rest on bricks at about every 8 ft. distance. The pipes should be locked together by means of what are technically called expansion joints.

If frames are arranged against the side of the house, some can be turned into heated pits, if desired, by connecting pipes from the main building.

Following the principle that no waste should be allowed in a garden, all material from the stokehole should be used in various ways - the cinders being burnt, clinkers used for drainage and as a foundation for path-making, ashes for the same purpose, and also as a plunging medium in frames, etc. A delightful fernery can be constructed of clinker coated with ordinary brown sand, made adhesive by first covering with some liquid compost and water. Soot saved from fires is, needless to say, of the greatest value in the garden.

A greenhouse is, properly speaking, a house in which plants are reared for decorative purposes, and from which they are afterwards transferred to the garden, dwelling-house, or conservatory, if this additional structure exists. It is also used for sheltering delicate plants during winter, and for storing half-hardy plants and bulbs, planted out of doors in summer, but which are at rest during winter, such as dahlias, begonias, and so on. A temperate house is one in which the temperature should not fall at any time below 450, or rise above 650. Merely to preserve many plants, a minimum temperature of 40° will suffice.