Orchid winter care tips: master these points for a safe winter
Orchids stop growing in winter, but how well they are managed during this period directly affects how well they grow the following year. Some people, through improper winter management, end up with frozen-to-death plants, frostbite, empty roots and black spot disease, and in severe cases the plants die. Therefore every orchid grower must pay attention to winter care for orchids, and in my view the following ten essentials must be mastered: first, master the correct timing for moving them indoors; second, spray disease- and pest-prevention chemicals before moving them indoors; third, pay attention to frost protection; fourth, ventilate regularly; fifth, prevent the potting soil from becoming too dry; sixth, prevent the potting soil from becoming too wet; seventh, guard against coal gas; eighth, guard against overheating; ninth, guard against wet leaves; tenth, guard against water getting into the orchid's crown.
1. Master the correct timing for moving them indoors
Our country is vast, and the temperature difference within the same season is very large, so the timing for moving plants indoors cannot be generalized; it should be decided according to local climate changes. In my view, if it is a Cymbidium goeringii (spring orchid), it is best to choose the day before the weather forecast says frost will appear the next day. Some people move them indoors when the temperature is below 10 degrees; I think this is not good for the development of flower buds. Moving them indoors too early will inevitably lead to fewer flower buds or even no flower buds the following autumn. So as long as the temperature is not below freezing, the spring orchid should be given more low-temperature hardening at 10 degrees to 0 degrees. At such temperatures the orchid's tissues can also become fuller and healthier, and the new shoots the following year will be strong and vigorous.
2. Spray disease- and pest-prevention chemicals before moving them indoors
When the temperature is below 5 degrees, choose clear weather and spray once with an 800-fold dilution of thiophanate-methyl or carbendazim. If there are scale insects, also spray once with an insecticide such as cobalt oxide, which can prevent diseases caused by the higher greenhouse temperature after the plants are moved indoors.
3. Prevent freezing
The room where orchids overwinter can be a greenhouse (a glass room that gets sun during the day), an ordinary room or a plastic shed, but the minimum temperature must ensure the orchids do not go below I degree, to prevent frostbite. If it is below zero degrees, it is harmful to any orchid, and under no circumstances should the orchids be allowed to freeze. When it is too cold, use an electric heater to raise the temperature.
4. Ventilate regularly
To keep orchids from freezing, they also must not be kept for a long time in a place without ventilation or air movement, as this will cause the orchids to freeze and damage, and by spring black spots easily appear on the orchid leaves. The correct method is to open windows and doors promptly when the temperature is high, to promote air convection, but guard against cold northwest wind. Apart from severe freezes, it is best to open the windows for air at noon.
5. Prevent the potting soil from becoming too dry
In winter, orchids stop growing and their water requirement decreases. Because orchids have fleshy roots, generally cutting off water can keep them alive, but if the potting soil stays on the dry side for a long time, healthy orchid roots will become empty roots, and this will not show on the orchid leaves for a while. If it does show on the orchid leaves, the orchid roots have already been badly damaged, and in severe cases they have already died of dryness. This problem often arises from a one-sided understanding of "not wet in winter": when the orchid soil looks dry, only moistening the edge of the pot, and when the surface soil looks wet, thinking the orchid has been thoroughly watered, causing the orchid roots to dry out completely and die. The correct approach is "do not water if not dry" and "when watering, water thoroughly." A potting medium that is too dry can be soaked thoroughly by placing the pot in water.
6. Prevent prolonged excessive wetness
"Not wet in winter" means the orchid pot must not stay very moist for a long time, and it is even more important to avoid watering heavily again before it has dried after a heavy watering, as this will undoubtedly rot the roots. When the orchid pot is too wet after thorough watering, it can be put in the sun and given some air until the potting soil no longer looks very wet.
7. Guard against coal gas fumes
When heating the orchid room, do not use a coal stove; only use an electric heater and infrared light bulbs. These heaters must also be kept at a certain distance from the orchids (to prevent scorching the orchid leaves). If there is no dedicated orchid room, the orchids must be placed where coal gas cannot reach them. Because when orchid leaves come into contact with coal gas, black spots will inevitably appear on the leaves, so this must be avoided as much as possible.
8. Guard against excessive heat
In winter orchids are already dormant, and too high a temperature is not good for orchid dormancy. What is most taboo is keeping orchids in temperatures that suddenly rise and fall, which will make the orchid plants weaker and prone to illness. Therefore the orchid pots should not be close to heaters, and sunlight also needs appropriate shading.
9. Guard against wet leaves
In spring, summer and autumn, when orchid leaves are wetted by watering, because it is the orchid's growing season, the orchid itself needs a large amount of water, and with outdoor ventilation the leaves can be dried immediately, so black spots are not likely to appear. But if the leaves are wet in winter and the plant is placed in a greenhouse or room, because there is no ventilation, black spots are very likely to appear on the orchid leaves. So unless the leaves are covered with dust, it is better not to spray the orchid leaves. If the orchid leaves really are covered with dust, then of course you can choose a clear, frost-free noon to water the leaves once, open the windows until the orchid leaves are dry, and then close the windows.
10. Guard against water pouring into the orchid crown and rotting the crown
When watering in winter, it is best to pour the water in from the edge of the pot, and not to pour water into the orchid crown. If it is poured in by accident, use a dry cloth strip to absorb the accumulated water in the orchid crown, so as to prevent crown rot.
If the above ten points can be achieved, your orchids can pass the winter safely and healthily and welcome healthy growth next year.