Orchid Winter Care Techniques: Do These Things Well to Get Through Winter Safely
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, due to improper winter management, end up with frozen-to-death plants, frost damage, hollow roots and black spot disease, and in serious 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 time to move them indoors; second, spray disease- and pest-prevention chemicals before moving them indoors; third, pay attention to frost prevention; 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 pouring into the orchid's crown and rotting it.
1. Master the correct time to move them indoors
Our country is vast, and temperature differences within the same season are very large, so the time to move them indoors cannot be generalized; it should be decided according to local climate changes. In my view, if it is a Cymbidium (Chinese orchid), it is best to choose the day before the weather forecast says frost will appear tomorrow to move it indoors. Some people move them indoors when the temperature is below 10 degrees; I think this is not good for the development of flower buds, and moving them indoors too early will inevitably lead to fewer or even no flower buds the following autumn. So as long as the temperature is not below freezing, the Cymbidium 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 following year's new shoots 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 solution of thiophanate-methyl or carbendazim; if there are scale insects, also spray once with an insecticide such as cobalt oxide nitrogen, which can prevent diseases caused by the higher greenhouse temperature after the orchids are moved indoors.
3. Prevent freezing
The room where orchids overwinter can be a greenhouse (a glass room that can get sunlight during the day), an ordinary room or a plastic shed, but the minimum temperature must ensure the orchids do not go below 1 degree, to prevent frost damage. If it is below zero degrees, it is harmful to any orchid, and under no circumstances should the orchids be allowed to freeze. When the weather is too cold, use an electric heater to raise the temperature.
4. Ventilate regularly
To keep the orchids from freezing, you also must not keep them in a place without ventilation for a long time, as this will cause the orchids to freeze and damage, and in spring black spots easily appear on the orchid leaves. The correct method is to open windows and doors in time when the temperature is high, to promote air convection, but guard against cold northwest wind; apart from severe freezing, it is best to open windows for ventilation at noon.
5. Prevent the potting soil in the flower pot 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 hollow roots, and this will not be reflected on the orchid leaves for a while. If it is reflected on the orchid leaves, the orchid roots have already been badly damaged, and in serious cases they have already dried to death. This problem often arises from a one-sided understanding of "not wet in winter": when seeing the orchid soil dry, only moistening the water along the edge of the pot, and when seeing the surface soil wet, thinking the orchid has been thoroughly watered, thus causing the orchid roots to dry to death completely. The correct approach is not to water when not dry, and to water thoroughly when watering. A potting medium that is too dry can be placed in water to soak the pot thoroughly.
6. Prevent prolonged excessive wetness
"Not wet in winter" means the orchid pot must not remain very warm for a long time, and it is even more important to avoid heavy wetting again before it has dried after heavy wetting, as this will undoubtedly rot the roots. When the orchid pot is too wet after being watered thoroughly, you can let it get some sun and some air until the potting soil no longer looks very wet.
7. Guard against coal gas fumes
When heating the orchid room, a coal stove must not be used; only an electric heater and infrared light bulbs can be used. These heaters also need to be kept at a certain distance from the orchids (to prevent burning 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 the orchids are already dormant; if the temperature is too high it is not good for the orchids' dormancy, and the worst thing is for the orchids to be in temperatures that fluctuate between high and low, which will make the orchid plants weaker and prone to illness. Therefore the orchid pots should not be close to the heater, and sunlight also needs appropriate shading.
9. Guard against wet leaves
When orchid leaves are wetted by watering in spring, summer and autumn, 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 do not easily appear. But if the leaves are wet in winter and the orchid 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, do not spray the orchid leaves; if the orchid leaves really are covered with dust, of course you can also choose a clear, frost-free noon to water the orchid leaves once, open the windows until the orchid leaves are dry, and then close the windows.
10. Guard against water pouring into the orchid's crown and rotting the crown
When watering in winter, it is best to pour the water in from the edge of the pot; do not pour water into the orchid's crown. If it is poured in by accident, use a dry cloth strip to absorb the water accumulated in the orchid's crown, so as to avoid rotting the crown.
If the above ten points can be done, your orchids can get through the winter safely and healthily, and welcome healthy growth next year.