How to care for orchids in winter? Master these five care essentials

1. Adjust water and fertilizer to promote bud development and growth

Orchids enter dormancy in winter, so adjusting water and fertilizer management becomes inevitable. First, reduce watering. There is an orchid saying, "Do not keep wet in winter," which is a clear requirement for winter watering. Winter temperatures are relatively low, and during dormancy the vegetative growth of orchids nearly stops while reproductive growth proceeds slowly. In addition, the transpiration of the microenvironment inside the pot is small, so orchids need less water. This requires us to reduce both the amount and frequency of watering compared with spring and autumn: water less, and lengthen the interval between waterings. You can alternate between watering thoroughly and moistening the pot surface to keep the potting medium in a moist state. In winter, never let the potting medium dry out; otherwise, with even slight freezing, the orchid roots will become hollow and the plant will die. Second, apply fertilizer in diluted amounts. Dormant orchids basically do not absorb fertilizer, but spraying a small amount of dilute phosphorus-potassium fertilizer on the leaves is beneficial to orchids. It can both provide nutrient delivery to orchid buds produced in autumn and winter and to flower buds currently developing, and help orchids resist cold so they overwinter safely. This is because the phosphorus element in fertilizer can lower the freezing point of the plant body, and the potassium element can increase the cellulose in the plant body, promoting tougher stem and leaf cortex. Experienced orchid growers apply phosphorus-potassium fertilizer at the beginning of winter, which can effectively enhance the stress resistance of orchid plants and reduce the occurrence of diseases. However, in winter it is best to stop applying nitrogen fertilizer, so as not to disrupt reproductive growth, affect orchid flowering, and reduce orchid resistance. 

2. Capture light and harden the plants to enhance resistance

For orchids to pass through winter smoothly, enhancing their resistance becomes a major winter orchid task. First, increase light exposure. Winter sunlight not only greatly helps plump up the pseudobulbs, but also greatly benefits growth and reproduction the following spring. Before moving them indoors, while ensuring ventilation, let the orchids receive as much light as possible. Open shade nets and reed screens fully, and both direct and angled sunlight are fine, so that orchids accumulate more energy through photosynthesis. Second, harden the plants appropriately. Low winter temperatures not only promote the growth and strength of flower buds that orchids have already formed, but also play an important role in prompting the buds on pseudobulbs to differentiate into flower buds the following year. Therefore, when temperatures in early winter are not too low, do not rush to move orchids indoors. Letting orchids undergo a period of low-temperature hardening helps enhance their overwintering resistance. Spring orchids and Huilan in particular need the tempering of "vernalization." Third, apply a little fertilizer. As mentioned above, in clear and warm winter weather, applying a small amount of phosphorus-potassium fertilizer helps improve orchid resistance. If phosphorus-potassium fertilizer and aspirin are applied alternately, the effect is even better.

3. Keep warm and prevent freezing for safe overwintering

An important management measure for winter orchid care is doing a good job of freeze prevention. When the temperature is below 0 degrees, it is harmful to any kind of orchid, and under no circumstances should the orchid pot surface be allowed to freeze. If in winter you find the upper surface of orchid leaves covered with dense, fine small spots while the underside is intact, that is caused by freeze damage. To do a good job of freeze prevention, first, you can keep the pot surface warm. You can place sphagnum moss on the pot surface to provide warmth and moisture retention. Second, orchids should be properly positioned. The cold tolerance of orchid species from high to low is: Huilan, Chunlan, Jianlan, Hanlan, Molan. When severe cold arrives, orchids should be moved indoors promptly, or moved under eaves and sheds for care, strictly preventing frost and snow damage. If the environmental temperature for Chunlan and Huilan can be kept above 0 degrees, and the temperature for Jianlan, Hanlan, and Molan kept at 3 to 5 degrees, orchids can be ensured safe overwintering. Third, take warming measures. Modern orchid rooms have air conditioning to control temperature, but attention must be paid to humidification. Simple orchid rooms can use electric heating rods or pot charcoal fires for heating. Some orchid growers use a gas stove to light a fire for heating in the orchid shed, and the effect is also good, but care must be taken to prevent gas poisoning. Some orchid growers fill a thermos with hot water, open the lid, and use it to supply heat and raise the temperature for a balcony orchid room, which is also worth learning from.

4. Protect flowers and promote buds to ensure results

Carefully tending flower buds and leaf buds in winter is a key essential for ensuring fragrant flowers and strong buds in the coming year. First, protect the flower buds. It is appropriate to keep the orchid room temperature at 1 to 18 degrees and humidity at 60% to 70%. According to the principle of removing the weak and keeping the strong, thin the flowers appropriately. For those whose flower quality has already been determined and which you want to produce more plants, the flower scape can be removed as soon as it emerges. The method is to pinch the flower bud with your hand and twist it 90 to 180 degrees, and a fungicide can be applied appropriately to the wound. For wild-collected plants whose flower quality has not been determined, just keep one or two strong scapes. If there are flower buds on both the front and rear growths, remove the weak buds on the rear growth and keep the strong buds on the front growth. Try to reduce unnecessary consumption that would affect budding and flowering the following year. Especially for freshly collected wild plants, particular attention should be paid to avoid the tragic outcome of flowers fading and the plant dying. Second, care for the leaf buds. As long as orchid buds that sprout in autumn and winter are properly managed, they can grow into large plants in the coming spring and summer. For orchid buds, grasp the principle of "appropriate watering and a small amount of fertilizer" and care for them carefully. Winter temperatures are low, and moisture does not evaporate easily, so special attention must be paid not to splash water or fertilizer into the bud center to prevent bud rot. If water or fertilizer is accidentally splashed into the bud center, use soft paper to absorb it dry.

5. Sterilize and kill insects to eliminate hidden dangers

Thoroughly eliminating hidden dangers from pests and diseases in winter is the first line of defense for preventing orchid diseases. First, comprehensively clean the orchid room. A clean and tidy orchid-growing environment is a necessary condition for reducing orchid diseases. After thoroughly renovating the orchid room, spray insecticidal and fungicidal agents on the walls, floor, pot walls, and orchid shelves so that dormant sclerotia and insect eggs have nowhere to hide. Second, use medicine regularly to sterilize and kill insects. If medicine is used once a week during the growing season, then in winter use it alternately once every half month or once a month for foliar spraying, interspersed with application by watering, which can strike at root diseases. If pest and disease control for orchids is done ahead of time in winter, and then another comprehensive disinfection is carried out in the coming spring at Jingzhe when fungi and insects awaken, the effect will be greatly improved.