In principle, a distinction must be made between two terms: the humidity of the air and the humidity of the soil, in the case of orchids, that is, the plant matter.
The humidity is an important factor in general for the care of the tropical plants in the room, especially of course for orchids. It is more difficult to create than pleasant light- or temperature conditions. However, it has been proven, that many orchids at about 50% Find suitable conditions for humidity. There are two different periods to consider when taking care of the rooms. In the months, where no heating is required, the air humidity is influenced by the climate; so it is largely based on the external conditions. This will make the statement, that with beautiful, dry weather in the room 50%, at cloudy, damp weather 60 to 80% Humidity are present. These values are completely sufficient for the care of many species. As soon as the heating season begins, is the influence of external weather conditions – so here the humidity – largely switched off; the conditions become less favorable for the plants. The humidity can be increased to a certain extent by placing bowls filled with water, without furniture u. a. get damaged.
Again, the dependence on the other growth factors is evident. Increasing light and increasing temperature – so sunny, warm weather – cause an increase in humidity, while conversely cloudy, cool weather does not require or even prohibit an increase in humidity. They are regulated in the plant window or in the greenhouse by spraying or misting water, until the desired degree of saturation of the air is reached. It is generally required, to keep the humidity lower at night than during the day. This measure is in contrast to the high nocturnal humidity in the tropics, which, however, is accompanied by constant air movement, which cannot be created here, at least not in the same form as in nature. In general, the rule applies, that the plants should not be sprayed in the late afternoon or evening. This opinion is controversial; some carers have good results using the opposite method. Because spraying leads to an increase in humidity, the night temperatures should then not drop below the daytime temperatures. Is it still the case?, if you increase the humidity even more, because according to a physical law, the humidity rises as the temperature falls. It decreases with strong sun exposure and increased temperature. This should allow the interplay between light, Temperature and humidity must be adequately explained.