Detailed Guide to Orchid Care Methods and Techniques in Summer and Autumn

Orchids originate from valley forests, naturally fond of shade and afraid of sun; they dislike extreme heat and dryness, and require a well-ventilated environment. According to this growth habit, orchid care in summer and autumn must pay attention to four points:

1. Shading and ventilation. Orchids need shading from early summer to the end of September, and the shading rate must not be lower than 70%. When shading, use shade nets for large quantities, and place small quantities on a north-facing balcony or under the eaves. During this period, the plants should be spaced out, with no less than 10 cm between pots. It is best to prop the pots up on bricks to increase airflow and allow ventilation and air exchange. In addition, it is also necessary to prevent pollution from harmful substances such as sulfur dioxide, hydrogen fluoride and dust, so as to promote healthy growth.

2. Cooling and humidifying. The suitable growth temperature for orchids is 20°C-28°C. Above 25°C they grow rapidly; above 32°C they are forced into dormancy, with growth at a standstill. When the temperature reaches 30°C, measures to cool and humidify must be taken. For those cultivated outdoors, river sand or plastic film can be spread on the ground; for those cultivated on balconies, place sponge under the pots and keep it moist regularly. Spray the plants multiple times a day and sprinkle water on the ground. For indoor cultivation, an air conditioner or electric fan can be used. Adjust the temperature below 30°C as much as possible, and keep the air humidity stable above 70%.

3. Watering and fertilizing. At present, most orchids are grown in soil, and mostly in pots. The moisture in the potting soil should follow the principle of "moist but not wet, dry but not parched." Watering should be done when the surface soil is slightly white; never water too much, as this causes root rot. From midsummer to early autumn, generally water thoroughly once in the early morning, and in the evening water as appropriate depending on how dry or moist the potting soil is. If the potting soil is found to be dry after noon, replenish water at any time. Although the weather gradually cools after mid-autumn, the air is dry; according to the requirement that "autumn should not be dry," the potting soil should be kept moist. Fertilizing orchids should follow the principles of small amounts, dilute concentration, frequent application and timely application, and this is even more necessary in summer and autumn. From May to September, fertilizer should be applied as appropriate according to different orchid species and different growth stages. For orchid plants in dormancy or when the temperature is above 30°C, suspend fertilizing. Liquid fertilizer is generally applied once every 15-20 days, with a fertilizer-to-water ratio of 1:10; indoors, use solid fertilizer. Large-scale production mostly uses chemical fertilizer at a concentration of about 0.1%. For foliar spraying, prepare the concentration according to the product instructions.

4. Disease prevention and pest control. Orchids are plants prone to many diseases and pests, especially severe in hot and humid seasons. Anthracnose peaks from June to September; carbendazim and thiophanate have good control effects. For southern blight, drench with a 500-1000 times dilution of chloramphenicol injection, once a day, for two consecutive applications, which can control the disease. Scale insects are a major enemy of orchids; adults can be removed manually, and during the larval hatching period from May to June, spray with chemicals to kill them. For aphids and whiteflies, spray with a 500 times dilution of 10% wettable powder, and two consecutive sprays are sufficient.