Greenhouses And Heating

It is a November call on a friend who has a house of Chrysanthemums which has led many an amateur gardener to buy a glass-house. The sight of the beautiful flowers at a period when his own garden is bare convinces him that there is something wanting in his establishment.

A greenhouse is certainly a very pleasant addition to a garden, and not on account of Chrysanthemums alone. A large number of winter-flowering plants can be grown in it, and flowers produced at a season when without it they would be scarce.

If the house is made in sections, attached by screws instead of nails, and stood on loose bricks, it can be taken down, packed up, and removed at any time. It can be made to lean against a wall, or to be self-supporting. A group of Chrysanthemums is easier to arrange in a lean-to than in a span-roof house, as tall plants can be put against the back wall, and lower ones grouped in front of them. But a span-roof, with flat stages, is a better type for a general collection of dwarfer plants, such as Calceolarias, Cinerarias, Cyclamens, Primulas, Zonal Geraniums, Bouvardias, Hyacinths, Freesias, and Tulips. And, as the gardeners in the public parks show us, Chrysanthemums can be made to look very nice in span-roof houses.

A lean-to house is best for Vines and Peaches, and a house that is built for these fruits should be put against a wall. The hot-water pipe system of heating is favoured, as heat radiated from the body of a lamp or stove is too dry and local. In the case of small houses an upright boiler can be let in the front of the house and fed from the outside. Pipes are connected at the back, one (the upper) being a flow, and the other (the lower) a return. They should rise an inch for every eight feet from the boiler. They may go down one side of the house only if cost of material has to be studied very closely, and if only a cool house is required; but it is better to take them round the end and down the other side, there connecting them with an expansion cistern through which water can be poured to fill the pipes and boiler until it stands half-way up the top pipe. Coke will serve as a fuel if it is broken up small, but not otherwise. Broken anthracite coal may also be used. Experience will soon teach valuable lessons in stoking, particularly in respect to banking up at night, and so keeping the fire going until morning. Gas and oil boilers may be fitted to pipes if required.

Fig. 90. - Span-Roof Greenhouse - Section.

a. Walls.

b. Front woodwork and glass, also ventilators.

c. Roof, with top ventilators.

d. Central stage.

e. Side stages. f. Hot-water pipes.