What are the micro-ecological characteristics of an enclosed balcony?

Orchidsare one of China's ten traditional famous flowers and a world-renowned famous flower. They are deeply loved for either their subtle fragrance or their elegant beauty, and have become an important species in modern urban greening and home environment beautification, and are even currently the most economically valuable "green stock". However, for urban residents surrounded by high-rise buildings, just like growing other flowers and plants, growingorchidswell is not an easy matter. The higher the floor, the worse the micro-environmental conditions, and the smaller the possibility of keeping them alive and growing them well. The emergence of enclosed balconies has alleviated this problem and provided a very promising path for popularizing urbanorchid growing. The enclosed balcony referred to here by the author means a balcony enclosed with glass windows in an aluminum alloy, steel, or wooden frame structure. It has some characteristics similar to a glasshouse greenhouse in horticulture. Compared with an open balcony, it has the characteristics of lower light intensity, smaller temperature difference, less disturbance from rain and wind, low humidity, a large temperature difference between the upper and lower parts of the balcony, small fluctuations between upper and lower floors, and being easily subject to artificial regulation. The following description is based on a third- or fourth-floor balcony facing southeast. 1. Light. The light duration is basically the same as that of an open balcony, but in terms of light quality, because ultraviolet rays cannot penetrate glass, when all windows are closed, ultraviolet radiation is equal to zero; differences in glass materials and the use of curtains can affect light intensity by 20-90%. Based on the author's practical results, shading is generally used in late spring and early autumn, and no shading is used at other times.Orchidsgrow very well. 2. Temperature. With the regulation of light, compared with an open balcony, the temperature shows obvious changes. When the winter temperature reaches -6°C, the nighttime temperature of the enclosed balcony reaches about 2 degrees; when the daytime temperature in summer reaches as high as 39 degrees, the balcony temperature after shading is 34°C, while at the same time the temperature of an open balcony can reach 43°C. But when the windows are not opened, the temperature in the first half of the night can be 4-5 degrees higher. As for the upper and lower layers within the balcony, the closer to the top, the higher the temperature. 3. Humidity. Due to human intervention and small airflow, the humidity of an enclosed balcony is generally around 70-90%. On rainy days or for a period after spraying water, it reaches above 90%, but during continuous rainy days it is somewhat lower than the atmosphere. The pattern of change through thefour seasonsof the year is basically the same as that of nature, only with a smaller range of fluctuation, and is closer to the physiological requirement of orchids preferring moisture. Contrary to temperature, the humidity in the upper and lower layers within the balcony is smaller above and greater below. Likewise, the transpiration rate of the soil surface in the middle of the balcony is equivalent to 2-3 times that of the balcony floor. Therefore, this factor should be fully considered when placing orchid pots. 4. Rain and wind. The unfavorable aspects of rainwater and wind volume for artificialcultivationoforchidsare mainly shown in their excess. There is an orchid saying that "do not keep them wet in winter," but according to local orchid-growing practice: "do not let them become waterlogged during the plum (rainy) season" appears even more important, because large amounts of rainwater during the plum season can bring about pest and disease reproduction and rotting of new plants; wind (air) is an important factor in growingorchidswell. "Linghai Lanyan" says: "Growing orchidstakes all-around ventilation as the first principle." But what is meant is a gentle breeze and maintaining smooth air flow. Local monsoons prevail, especially for those living on the 4th floor or above in high-rise buildings, where plants find it difficult to grow safely on an open balcony. An enclosed balcony, however, can freely regulate the required wind volume and rainfall by opening and closing windows, creating good conditions for orchid growth without the harm of excessive invasion. Wang Kairong