How to Grow Orchids? Master the Key Points of Light, Watering, Repotting, and Pest and Disease Control

Orchid growers have an old saying: "Three parts planting, seven parts management." Whether orchids grow well depends entirely on whether daily management is done properly; poor management easily leads to problems. Below, the orchid care experience that veteran growers have worked out over many years is organized for everyone's reference.

Skillful Adjustment of Light and Humidity: Half Shade and Half Sun, Better Dry Than Waterlogged

As for light, apart from winter, when orchids need to be moved indoors for care, in spring, summer, and autumn they should all be grown under a shade shed; only with suitable light and proper fertilizer and water can they have broad leaves, green color, strong scapes, and many flowers. The shading level of the shade shed is best adjusted flexibly and opened in the morning and evening so orchids can absorb dew. Orchids need half-shade, half-sun light, and during the flowering period they should especially be placed in a cool, shaded, and humid spot to extend the viewing time; in late autumn, stronger light can gradually be given, and in winter they should also be placed in a spot with ample light. Light requirements can be judged by the leaves: those with thick, fleshy leaves, yellow-green leaf color, or variegated leaves need more light, while those with thin and dark green leaves need less; Cymbidium goeringii and Cymbidium faberi need strong light, while Cymbidium ensifolium and Cymbidium sinense need weaker light.

As for humidity, orchids like a moist air environment, but the potting soil should be on the dry side; you can sprinkle water on the ground and the potting soil every day to increase humidity. Keep watering at seven parts dry, and in winter even more on the dry side; slightly dry potting soil can promote nutrient concentration and benefit flower bud differentiation, while too much moisture easily causes leggy growth or even root rot, so the lower part of the orchid pot should be filled with broken bricks and charcoal chunks for drainage. Before flowering, sprinkled water must not spray onto the flower scape, otherwise the buds will rot. In short, spatial humidity is more important than root-zone humidity. In addition, the optimal growing temperature for orchids is above 3-10 degrees; below this they are prone to freezing, and before a temperature drop, fertilizer can be sprayed to help the plants retain warmth; different species should also be planted separately to avoid affecting one another.

Repotting and Division Have Their Rules: Once Every Two Years, Disinfect Wounds

Orchids grow slowly, producing new roots and leaves only once a year, so generally you should wait two years before dividing the pot. When dividing, the soil should be thoroughly dry; if the fleshy roots are slightly wilted, you can tip out the orchid seedlings, shake off the old soil, and cut away diseased roots, old roots, and broken roots; even if they are pruned to have no roots, there is no need to worry. After washing clean, divide the orchid seedlings into 2-3 clumps, each retaining at least 3 or more pseudobulbs; apply stove ash or sulfur powder to the wounds, place in a cool, ventilated spot to dry until the roots turn white and soft, then plant into potting soil with a relatively high content of sand and gravel. Arrange the orchid roots naturally with the new shoots facing outward, leaving ample room for growth; planting must not be too deep, and it is best to leave half of the pseudobulb exposed.

Identify Diseases by Reading the Leaves, Early Prevention and Treatment in Summer and Autumn Management

Physiological diseases of orchids can be detected from changes in the leaves: yellow and thin leaves mean a lack of fertilizer; scorching gradually downward from the leaf tip means too much fertilizer or the use of raw fertilizer; scorching from the bottom upward means too much watering; yellowing in the middle of the leaf, black spots, or even scorching is caused by too great a difference between soil temperature and water temperature.

Summer and autumn care has another four key points. Shading and ventilation: from early summer to the end of September, the shading level should be no less than 70%; for large quantities, use shade netting; for small quantities, place them on a north-facing balcony or under the eaves; the spacing between pots should be no less than 10cm; place bricks under the pots to increase ventilation, and prevent pollution from sulfur dioxide, hydrogen fluoride, and dust. Cooling and humidifying: the suitable temperature is 20-28 degrees; above 25 degrees they grow rapidly, above 32 degrees they enter dormancy, and at 30 degrees you need to cool and humidify, for open-air sites by spreading river sand or plastic film on the ground, for balconies by placing sponge under the pots to retain moisture, spraying the plants and sprinkling water on the ground several times a day, and indoors by using an air conditioner or electric fan. Watering and fertilizing: adhere to "moist but not wet, dry but not parched," water when the surface soil is slightly white; in midsummer to early autumn, water once thoroughly in the early morning and supplement in the evening as appropriate, and if it dries at noon, replenish water at any time; after mid-autumn, keep the potting soil moist according to the requirement of "not dry in autumn"; fertilizing should be in small amounts, dilute, frequent, and timely, from May to September according to orchid species and growth condition, with liquid fertilizer once every 15-20 days at a fertilizer-to-water ratio of 1:10, using solid fertilizer indoors, about 0.1% chemical fertilizer concentration for large-scale production, and preparing foliar fertilizer according to product instructions. Disease and pest control: for anthracnose, use carbendazim and thiophanate; for southern blight, drench with chloramphenicol injection at 500-1000 times dilution; for scale insects, remove adults by hand and spray pesticide during the larval hatching period in May-June; for aphids and whiteflies, spray with 10% wettable powder at 500 times dilution.

If light, humidity, repotting, and disease prevention are all done well, orchids will naturally have lush leaves and abundant flowers. Friends who love orchids, these management key points must not be ignored.