MISCELLANEOUS AIDS AND GADGETS FOR GREENHOUSES
In all greenhouses potting has to be done at some time or other. If there is no potting shed with a bench, it is worth making a small portable potting bench that can be put on the staging or on some other support when required. The bench is merely a wooden board of tray shape, best made to fit conveniently on the size of staging you have, but with only three sides. On this compost can be mixed and pots filled without it getting pushed off on to the surroundings and on to the floor, and scooping is also facilitated. So as to maintain hygienic conditions, the surface of the tray is best covered with an easily cleaned material like Formica or similar. An easily portable, lightweight, and clean potting bench tray can be made from sheet aluminium.
To keep compost clean and hygienic, a few plastic bins such as small dustbins, or buckets with lids, are useful. All compost materials should be kept in clean covered containers too. A soil steriliser is essential if you are to make your own composts. Although it is possible to improvise one, it is far better to buy a proper steriliser. An electric type is the most convenient. Sizes to suit all requirements are available, and they are not expensive. It is much cheaper to make your own seed and potting composts if you have the time and materials. Sterilisers to be used with gas rings or primus stoves are also obtainable.
Humidity of the greenhouse atmosphere is often an important consideration. To help in seeing just how much moisture there is in the air, a direct reading hygrometer may be useful, especially for beginners. This is a small dial-like instrument costing little. As well as giving readings in per cent relative humidity, it should indicate wet, normal and dry air conditions for simplicity.
For assessing watering requirements a moisture meter may be also useful to beginners. This works on the principle of electrical conductivity but the technical explanation is not needed here.
The instrument consists of a probe attached to a little meter which gives readings as wet, moist or dry. The best form of the moisture meter is the IMA meter. This has the scale graduated in numbers. The meter is supplied with a site of guide tables giving the optimum readings for a wide range of plants and cultural operations. It takes much of the guesswork out of the task of watering and is especially recommended for beginners who tend to be too heavy with the water can.
Another gadget that can often be useful is the frost forecast thermometer. This is actually a kind of psychrometer – another instrument for measuring humidity. Its scale gives a good warning of the likelihood of frost if the instrument is properly placed and maintained. This is especially useful if you have garden frames which can be protected by covering at night, and also draws attention to a check of the greenhouse heating.