Efficient greenhouse insulation is essential to keep heating costs down and to prolong the season of an unheated structure. The most efficient means of insulating your greenhouse is to install double-glazing or triple-glazed polycarbonate during construction. Both these systems retain the heat well and offer excellent light transmission.

However, if your greenhouse or conservatory has not been installed with double or triple-glazing, there are a number of other more temporary insulation systems that may be installed.

Thermal Screens

Thermal screens may be used to conserve heat. These sheets of clear plastic or laminated fabric may be drawn vertically across the eaves at night to prevent heat from escaping through the roof, thereby trapping the warmth for the plants below. Alternatively, they may be used horizontally to partition off unused areas of the greenhouse. This allows the gardener to heat a small portion of the greenhouse to overwinter tender plants or raise seedlings without wasting money or energy heating the unused areas.

Before buying a greenhouse, try to think carefully about the type of work that you intend to carry out there; a greenhouse used mainly for sheltering tender plants will usually have lower space requirements to one used primarily for propagation and growing on. Try not to skimp on the size of the greenhouse you choose, as it will certainly seem much smaller once it is filled with plants. However, do bear in mind that a larger greenhouse will cost more to heat in the winter than a smaller one. One option would be to buy a greenhouse that can be extended; alternatively, thermal screens may be used to partition off unused sections during the winter to save heating costs.

A good minimum practical size for a general-propose greenhouse would be 2 m (6 ft) by 2.5 m (8 ft); smaller structures will be prone to sudden fluctuations in temperature, especially in summer when they may undergo a rapid build-up of heat. A six foot wide greenhouse will allow for a set of 2 ft wide staging on each side, with a 2 foot working area running between them. You will need a wider structure (8 ft) if you need wheelchair access or if you want to be able to bring a wheelbarrow inside.

You may find that many small greenhouses have fairly low eaves and ridges, which may mean that you have to stoop when working at the staging. This can become very tiring even after a short period; consider digging out a sunken base or raising the structure up onto a brick layer to gain more height.

Staging is an important greenhouse accessory that will allow you to use all the space in your greenhouse, conservatory or polytunnel efficiently. Staging also encourages healthier plant growth as it brings the plants closer to the light. You may want to consider fold-away staging; this will allow it to be used to propagate and grow on young plants in the spring, after which it may be removed to grow summer border crops.

Materials

Staging should be study enough to support the often considerable weight of plants, pots, compost and watering systems. Wood staging can be an attractive choice, and works especially well in wooden greenhouses or conservatories. Aluminium staging is long lasting, maintenance-free and will not rust, and so is ideal for use in the damp atmospheres of a greenhouse.

Dimensions

The majority of staging benches are a standard 45-60 cm (18-24 in) width from the back to the front, although wider models are available. However, do bear in mind that it will be very difficult to reach to the back of very deep staging. Make sure that you choose a staging with an appropriate working height for you; 75-90 cm (30-36in) is usually the most convenient. Lower versions are also available, which may be useful if you intend to sit down whilst working at your staging.

Positioning

Staging is usually positioned along the sides (and possibly one end) of a greenhouse, leaving a central pathway between them, although large greenhouses may place the staging in the centre, with a pathway around the edges. If the greenhouse is arranged so that one side houses the staging whilst the other contains an area for border crops, the staging should be positioned on the side that will cast the least shade on the border area.

When placing staging against the sides, always ensure that you leave a generous gap between the staging and the greenhouse to allow air to circulate freely.

Free Standing Systems

Free standing staging provides the greenhouse with a flexible system of extra space that may be dismantled or assembled whenever necessary. This can be particularly useful if you need additional space to grow seeds and bring on plants in the spring. However, free standing staging should also be sturdy enough to provide a permanent area to grow and display plants.

You may want to consider buying a system that may be added to easily in the future; for example by adding extra sections to increase the staging length, additional shelves below the staging surface or even extra tiers above the existing staging.

Integral Systems

If staging is required for only part of the year, you might want to consider installing an integral system. This is an open mesh staging that anchors onto the greenhouse wall using a number of study hinges bolted into the glazing bars, and is supported by two legs that clip onto the front edge of the staging. By simply removing the legs, the hinges allow the staging to be folded flat ...