Correct watering methods for Chinese orchids in the north

Chinese orchids are acid-loving plants that grow in rainy, high-humidity environments. Life is inseparable from water, because water is a raw material for photosynthesis and also a component of protoplasm. Water is the most abundant substance in the body of Chinese orchids. According to measurements ofCymbidium ensifolium, the plant's water content is 67.3%, the root water content is 85.6%, the pseudobulb water content is 52.9%, and the leaf water content is 50.9%. The water consumption pattern of Chinese orchids: mainly evaporation from the potting medium, and the amount of evaporation increases with rising temperature and decreases with increasing relative air humidity; wind speed also has a great influence. Next is transpiration from the leaves, and the amount of transpiration increases with the increase in plant growth, while environmental conditions also play a major role... Cymbidium goeringiiIn Hangzhou, the main producing area, the annual precipitation is 1489 mm, and the annual average relative air humidity is 80%;Cymbidium ensifoliumIn Yongding County, Fujian Province, the main producing area, the annual precipitation is 1670 mm, and the relative air humidity varies between 76%-82%, being greatest from April to July, often above 80%. In Jinan in the north, however, the annual precipitation is only 692 mm, which is 49.5% of Hangzhou's and 43.3% of Yongding's; the relative air humidity is only 65%, about 15% lower than Hangzhou and Yongding. The comparison of monthly relative humidity is as follows: As shown in the table above, except for August, when the relative air humidity in the two places is equal, Jinan is lower in all other months. Particularly notable is that Yongding County is highest from April to July, while Jinan is lowest from March to June. As for water quality, the south mostly uses natural precipitation, while water in the north mostly contains calcium and is weakly alkaline; the best is neutral. In short, the relative air humidity (especially in spring) and water quality both cannot meet the requirements for the growth and development of Chinese orchids, so appropriate measures must be taken to ensure their normal growth. The authorgrows orchidsusing fish pond water, treated with oxalic acid. For 90 jin of water, 6 grams of oxalic acid, after treatment the pH is 5.5-6.0. To increase humidity, potted orchids are chosen to enter the greenhouse in winter, then moved into a flower pond in early March. The pond is 95 cm deep, and flower racks are used to adjust the height of the potted orchids, with plastic film for cold protection and shade netting for shading. Both the greenhouse and the flower pond make humidity easy to regulate. When the rainy season arrives at the end of June and the beginning of July, the relative air humidity increases, so the potted orchids are then moved into a flower shed. In autumn they first enter the flower pond, then the greenhouse. As for watering time, according to the water requirements of Chinese orchids, the climate, and the current state of granular potting medium, immersion irrigation and flushing irrigation are the main methods, with sprinkler irrigation as a supplement. In different seasons, immerse or flush once every 3-7 days; when the weather is cold, do it from 10-12 o'clock. On days without irrigation, spray to moisten the upper potting medium in the pot; in spring, water from 8-10 o'clock, sprinkle irrigate once from 11 o'clock to 3 p.m., and spray around 4-5 p.m. to moisten the upper potting medium in the pot. For mixed potting medium, immersion irrigation is the main method, with sprinkler irrigation as a supplement. In short, the potting medium must be kept regularly moist. With granular potting medium, prevent the upper part from becoming too dry; with mixed frame medium, prevent the lower part from becoming too wet. When the weather is cold, it may be slightly dry. In Jinan city,balconyorchid growing, increasing the water surface, placing potted orchids above the water surface, and regulating humidity also achieved good results. "Dry orchids, wet chrysanthemums" is relative; "compared with chrysanthemums, orchids should be drier": for orchids themselves, "when dry and wet are compared, wet is more harmful than dry." But moist potting medium is still beneficial to the growth of Chinese orchids, because water is a raw material for photosynthesis, and without the raw material, photosynthesis cannot proceed. Moreover, if too dry, root water regulation to the stems and leaves is affected, which in turn affects the normal activity of the root system, so "moisture in the potting medium" should be emphasized. In summer dog days rain, when the difference between water temperature and potting medium temperature is too great, water should be applied after the rain to regulate the temperature of the potting medium. Ensure the root system is within a suitable temperature range. If the temperature difference between precipitation and the potting medium is small, and it is not a rainstorm, washing with rainwater is even more beneficial. In high-temperature, high-humidity weather, such as when the temperature is above 25°C and the relative humidity is around 90%, fungal spores easily germinate, so ventilation and cooling are necessary, and fungicides such as thiophanate-methyl and Score should be sprayed, once every 5-7 days, especially on the stomata on the underside of leaves and on wounds of damaged leaves, to prevent fungal invasion. The famous orchid grower Wang Shuping advocated "watering at night; if watering in the morning, avoid light for one day." Under his specific conditions, good results were achieved. We should study this in depth according to our own circumstances. (Wang Tao)