Greenhouse Equipment

An extremely wide range of equipment is available for greenhouses, some essential and the rest aiming, in one way or another, to make life easier for the gardener. Naturally, we all have our own ideas about what equipment is worth spending money on and what can be done without. My intention now is to briefly outline the most essential and interesting component parts of a greenhouse and related ancillary equipment, defining their role in the scheme of things.

There is certain basic equipment for which every greenhouse gardener will feel a need, for example, staging (even a greenhouse in which the plants are normally grown in beds, can benefit at times from the erection of portable staging), a well-balanced watering-can and, possibly, a water tank, with mains supply. There are few things more irksome than having to carry water from the home to the greenhouse day in day out. A professionally installed supply of electricity is important, too, not only for providing lighting so that work can continue in the greenhouse after dark, particularly on winter evenings, but also to provide power for the many pieces of electrical equipment that are now available for greenhouse use. Ventilators and shading devices are extremely important.


As I have already said, staging is not always required in the greenhouse, for some crops, such as tomatoes, are best grown on the ground or in rings of prepared soil standing on a bed of ashes or gravel. But staging is convenient for the cultivation of many pot plants and, if it can be screwed or bolted together, it can be removed from the house when necessary.

Staging can be either open, ie. made of wooden slats, with air spaces between, or closed, ie. made of concrete or another solid substance usually covered with a layer of gravel or small stone chippings to hold moisture. Open staging causes dry air to circulate around the plants and does not usually provide such a good growing atmosphere for them. For most purposes staging at one height, usually about 2 ft. above ground level, is convenient but in wider greenhouses or where displays of plants are to be arranged, it is sometimes convenient to have tiered staging at several levels.

Insulating Materials

The amount of artificial heat needed to maintain a greenhouse at any desired temperature can be reduced by proper insulation of the side walls and the glass area (with clear polythene sheeting) and by eliminating all cracks through which cold air may enter or warm air escape. Wooden-sided houses are particularly in need of extra insulation and this may be done with glass wool or any other heat-insulating material.

Lengths of glass fibre, the kind used by builders for insulation, may be placed against the wood on the inside of the house. These add further to the insulation and also protect the woodwork from water.

If the greenhouse is lined with clear polythene sheeting during the winter months this gives the effect of double glazing and can reduce the cost of heating the house by almost half. It can be fixed in position very easily with a stapler, placing a piece of strong paper between the stapler and the polythene to avoid tearing. The polythene is stapled or otherwise fixed (drawing pins or tacks can be used) onto the glazing bars, running up and down these rather than across. In this way condensation runs down to the eaves rather than dropping onto the plants. It should not be placed over the ventilators. Naturally, it does reduce the light factor within the house to some extent and this must be balanced against the saving in fuel.

Propagating Frame

A small propagating frame to stand on the greenhouse staging, with soil-warming cables in the sand-covered base and air-warming cables round the sides, is of the greatest value. I use such a frame for rooting cuttings such as carnations and chrysanthemums, and even more for seed germination in spring. The great advantage of a propagating frame is that the temperature necessary for plant increase does not have to be maintained in the greenhouse as a whole. Fully automatic models are available with a thermostat giving a wide range of temperature options. It will be readily understood how much more scope such a unit gives the gardener in terms of extended propagating seasons and general interest.

Mist Propagation Unit

A more ambitious aid to propagation is what is known as a mist propagator, a device which has made it so very much easier to root cuttings of shrubs of many different kinds (some notoriously difficult to root by other means) and other plants. Like so many other ingenious pieces of equipment it is more simple than might be imagined. Basically the unit consists of a device which ensures that the leaves of cuttings are kept permanently moist by subjecting them to a fine mist spray either at set intervals or when moisture evaporation activates a water valve. Such a unit is normally set up on the greenhouse staging over a bed of sand or other rooting medium. Soil-warming cables are threaded through the bed and can be thermostatically controlled to provide a temperature of about 18 to 21 °C. (65 to 70°F.).

Capillary Bench Watering

This method of watering ensures that pot plants get water automatically, when they need it and in quantities appropriate to their needs. The value of this equipment to the busy gardener needs no emphasising. Again, the system of operation is notable for its simplicity.

Water is supplied from a feed tank or large jar to a sand tray on which the pot plants are stood. The water is fed by gravity into channels beneath the sand and the height of the water tank is adjusted to ensure that the water level in the sand tray is just below the surface. The water supply comes from a tank connected to the mains supply and controlled by a ball valve, or from a large bottle which must be regularly topped supply water directly to the pots, or they can rest on a up by hand. The plants in the pots take up water from their compost as they need it, and this in turn is replaced by capillary action between the compost and the wet sand. Plastic pots have a distinctive advantage in this respect over clay ones for their thin bases make it easier for contact between compost and sand, which is essential if capillary action is to take place. Clay pots, however, must have a piece of wick threaded through their base to connect the water supply with the compost. Water is only taken up as it is needed so this is a far more precise method of watering than the traditional way with a watering-can.

Trickle Watering

This system utilises a plastic hose with outlet nozzles at set intervals along the length corresponding to the average distance between quite closely set pots. The hose is connected to a storage tank which fills slowly from the mains and releases its water when full. Plants in pots or beds can thus be given set quantities of water automatically at determined time intervals. It is not such a precise method of watering as the capillary bench, but nevertheless it is useful for the busy gardener. Outlet nozzles which are not needed can be blocked off.


However much use is made of automatic watering devices, there will always be a place for the watering-can. It is important that it should be well balanced, and the kind with a long spout enabling plants at the back of beds or staging to be reached easily is the best choice for greenhouse use. More and more plastic is taking over from metal in this field, and it will be generally agreed that its lightness, durability and, often cheapness give it a distinct advantage.

It is essential to have a line rose attachment for watering newly potted plants and seedlings and for spraying plants overhead. A coarse rose is also useful for damping down and for other jobs where a heavier spray is required. For watering pot plants I would recommend a can of 1 to 1-½-gal. size, but much depends on individual circumstances: how much water do you wish to lift, how far will you have to carry it?

Soil Moisture Meter

A tensiometer or soil moisture meter which indicates whether the soil is dry, moist or wet is a useful item of equipment. When a pointed probe is inserted in the soil a needle gives a reading on a calibrated scale.


Maintaining an equable temperature in the greenhouse is essential if plants are to give of their best. For this reason a thermometer is an essential item of equipment. The most useful kind is that which registers maximum and minimum temperatures by leaving a small needle in position as the mercury retracts. Many thermometers of this type are reset with a magnet but the more expensive ones have push-button readjustment. A soil thermometer is useful for soil sterilisation. This being calibrated to include the high temperatures involved.

Soil Sterilisers

A small soil steriliser with which to partially sterilise the soil one intends to use for potting and plant propagation, is enormously useful. Several different methods of sterilisation are used but the best and most convenient is steam sterilisation with an electric soil steriliser unit. These are compact and reasonably cheap to buy. If you do not wish to go to this expense, though, it is possible to do a good job with an ordinary bucket, standing this in a copper of boiling water. The idea is to raise the temperature of the soil to about 93°C. (200°F.) and keep it at that for about 20 minutes.

Flower Pots

I find it strange to think back to the time when we were told that plants would grow in nothing but porous clay pots. There was the introduction of the glass pot but that did not last long and we went back to clay: but now plastic pots have almost superseded the clay ones. This is not surprising considering the advantages: lightness, durability, case of storing and cleaning and cheapness compared with their clay counterparts. I do not think that the plants are any the worse for the changeover and the pots are certainly much more pleasant to handle. There is one thing, though, on the debit side; we have to be very much more careful not to overwater. Plants in plastic pots dry out less quickly than those in clay pots, and it is very easy to cause waterlogging.

The accompanying diagram shows the sizes of flower pot available. The most frequently used are the 3-½-in., 5-in., 7-in. and 8-in. sizes. The 2-in. size is useful for rooting single cuttings.

Seed Boxes

In seed boxes, too, plastic is rapidly taking over from wood. These have a standard measurement of 14 in. by 8-½ in. by 2 in.

A ‘Presser’

This is a wooden block with a short handle which is used for firming and levelling compost before seed sowing. It can be easily made at home.


For grading soils to the texture necessary for potting and seed sowing a sieve is essential. For general purposes a 3/8in. mesh sieve should be used with a finer one for lightly covering seeds with compost after they have been placed in position. This last can easily be made at home from a small wooden box by re-placing the bottom of the box with a piece of perforated zinc.

A Measure

There is no need to emphasise the value of a measuring cylinder or jug in the greenhouse. It is needed frequently for measuring liquid feed, insecticides and fungicides.

A Bucket

The uses for this simple piece of equipment need no explanation. In this area, too, plastic now holds top place.


Pest and disease control must always be at the back of one’s mind for any infestation or infection in the confines of a greenhouse spreads very rapidly indeed. A small hand sprayer for insecticide and fungicide application is a ‘must’. One that can be used for spraying the plants with water during the hot weather is also useful.


These are available in all shapes and sizes, in plastic, metal and wood, which one chooses is purely a matter of personal preference.

Tying Materials

There are various materials that are suitable for tying plants, and one or other should always be close at hand so that plants may be supported as soon as necessary. Raffia has been used for many years and it is reasonably priced. I find that it is easier to handle if it is soaked in water for a few hours before use. When tying small shoots, the raffia can be split and when stronger ties are needed, it can be doubled.

Fillis, a specially prepared soft twine, is available in various plys, and green gardening twine is also suitable. Split rings, the kind used for supporting sweet peas to their canes and small plastic- or paper-covered wires can also be used for greenhouse plants.

A Dibber

This is a small, wooden tool. Rather like a thick pencil. It is used to prepare holes for cuttings and seedlings. The end of this tool can be slightly pointed, but if it is too sharp it leaves an air space below the cutting or seedling with, probably, fatal results.

01. March 2012 by admin
Categories: Featured, Greenhouse Gardening | Tags: , , , , , | Comments Off on Greenhouse Equipment


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