At one time staging was nearly always supplied as the conventional slatted type made up from timber battens. It is now possible to have metal frameworks supporting either wire netting (or plastic) or sheet asbestos or similar material. In winter a net or slatted staging is desirable so that air and warmth can circulate, particularly in greenhouses equipped with a fan heater. The more recently introduced net type staging has given excellent growing conditions.
In summer, it may be convenient to cover such staging with plastic sheet or some similar material and spread this with any moisture-retaining substance such as grit, vermiculite, peat, or the like. This aids greenhouse humidity. Some people prefer to make their own staging from brick or concrete. This type of staging, being bulky, will hold considerable warmth.
It is quite a good choice for greenhouses where plants demanding moderate warmth are being grown. A substantial staging will absorb warmth during the day if the greenhouse has been heated by the sun, and evolve it during the night. Temperatures tend to fluctuate less easily. It will act in the manner of a storage heater.
Never take any form of solid or covered staging close up to the greenhouse sides. Always leave a gap of a few inches. This is to avoid currents of cold air, that may form in the vicinity of the glass, from falling and circulating on the surface of the staging.
The whole greenhouse need not be fitted with staging. Sometimes it is convenient to leave free the side getting the most light, so that plants can be grown from ground level. This particularly applies to glass-to-ground houses and those with glass-to-ground one side and a dwarf wall or boarded base the other.
This is useful in the spring when the greenhouse often tends to become full of plants being raised for bedding and various propagations from cuttings. It should not be put up so that shade is cast, to their detriment, on the plants below. In a bright, uncluttered greenhouse there is no point in putting plants high up near the glass on shelving in the mistaken belief that they get more light. Modern greenhouses with narrow glazing bars give almost as much light at staging level.
In winter there is a possibility that plants high up on shelving could become chilled if there is little or no artificial warmth.
The many beautiful trailing plants you can grow in hanging containers can also be displayed from pots on shelving. Most greenhouses are designed to take shelving and the makers supply the necessary Httings. For safety these should always be used, since pots of moist compost can be extremely heavy when lined up on a shelf.
Staging is essential in greenhouses with solid side walls more than 2 ft. in height and is useful in all houses in which pot plants or seedlings are to be grown. Its object is to keep plants near the glass where the light intensity is greatest and also to bring them close to hand so that they can be easily inspected, watered and tended.
Staging may be permanent or removable. If the latter, it is usually made of wood; if the former, it may be of wood, brick, or concrete. Open-slat staging is best for plants that like a dry atmosphere and free circulation of air, e.g. pelargoniums and perpetual-flowering carnations. Solid staging covered with clean gravel or small, sifted cinders is to be preferred for moisture-loving plants, e.g. tuberous-rooted begonias and gloxinias.