What is the critical temperature for frost protection of cultivated orchids?

Some say frost protection is unnecessary, while others say it is absolutely necessary. Which one is actually correct? Why can wild orchids survive temperatures of minus ten or more degrees Celsius? And where exactly is the critical point for frost protection of cultivated orchids?

Among orchids, Cymbidium faberi has the strongest resistance, whether to sun, heat, drought or freezing. So let us take Cymbidium faberi as an example: cultivated Cymbidium faberi is sensitive to freezing, and is not as cold-tolerant as wild Cymbidium faberi. Why? Because of the flower pot.

If you have observed carefully, you should know that after snow, the snow on dirt roads melts faster and earlier than on concrete roads, and the snow on concrete roads melts faster than on concrete bridges. This is due to ground temperature. Orchids on the mountain have their roots in the earth, and ground temperature protects them; together with mulch such as fallen leaves and snow cover, the orchid roots basically do not suffer frost damage.

But cultivated potted orchids are like concrete bridges, without any support from ground temperature. Once frozen, they freeze through entirely, and orchid roots will certainly die in a frozen state. This is true for Cymbidium faberi, let alone other orchid varieties.

Cultivated orchids need both low-temperature vernalization and frost protection. The critical point for frost protection, as defined by Haoshe Nongfu, is zero degrees. As long as it does not drop below zero degrees, the orchid will not suffer frost damage. And once it drops below zero degrees, there is no need to challenge the low temperature; to be safe, move them indoors quickly.