Issues related to the cold tolerance of succulent plants
Today, I bring you some experience with plants, specifically the knowledge about succulents and the issues related to their cold tolerance. Let's follow the editor to explore this together! Recently, many flower enthusiasts have asked how much low temperature succulents can tolerate. This question is really difficult to answer. Although I have some that are grown outdoors and some in sunrooms, the size of the pot and the health of the plant also affect the frost resistance of the plant. For experienced gardeners, this may not be an issue, but it is worth mentioning for new enthusiasts. I used plants from the Crassula family to test the frost resistance of general Crassula plants. This year, during the cold wave on the night of November 28th to the morning of November 29th, the lowest temperature was no lower than minus 3 degrees Celsius. The thermometer was taken when the sun just came out in the morning and was inside a roofed sunroom.
The first night of minus 3 degrees Celsius, most of the Crassula plants in the roofed sunroom showed signs of frostbite. The pictures clearly show the frozen state, with half of the grapes frozen and semi-transparent, the华丽 windmill plants almost transparent, and the cacti on the roof also somewhat abnormal.
After another night of normal care without heating, the temperature dropped to minus 4 degrees Celsius. The mercury thermometer had frost in the morning, indicating humidity in the air inside the roofed sunroom. Both sides of the insulation film were covered with thick frost. After two days of continuous temperatures of minus 3 to 4 degrees Celsius, the outdoor-grown String of Nickels died without a picture. The Ruby Red experienced frostbite but recovered after the sun came out. The华丽 windmill plants in the roofed sunroom were not so lucky and were almost all wiped out. Those under the eaves of the first floor were intact. The Black Wizard experienced frostbite but did not die, with its leaves slowly drying out. Half of the grapes were frostbitten, but after the temperature gradually warmed up, they have now recovered. If another night with such low temperatures occurs, they will all be wiped out. Many thick-leaved plants in the Crassula family have died.
The Sempervivum family is barely hanging on and can still be saved. The Dongyun series, although the leaves have a slight granular transparency (Romeo is the most frost-sensitive), generally recover after the temperature rises. Ebony can withstand minus 4 degrees Celsius with no problems, while variegated Crassula plants are mostly doomed. The皮氏石莲 variegation did not freeze the main stem and will likely recover in the spring. In general, after one day of minus 4 degrees Celsius, almost all Crassula plants will not die, although some may experience frostbite, they will generally recover after the temperature returns. On the second day of minus 4 degrees Celsius, about half of the Crassula plants will freeze to death, and even if the temperature warms up, it will not help. On the third day of minus 4 degrees Celsius, 80% of the Crassula plants will be beyond salvation.
The temperature of minus 4 degrees Celsius lasts for more than 5 hours each night, and only mercury thermometers are accurate. I have several mercury thermometers in my sunroom and a few outdoors, so taking the average reading is more accurate. Kerosene thermometers are not very accurate in extreme temperatures. By the way, at minus 4 degrees Celsius, some cactus species become transparent immediately, such as Qijiao丸, and are wiped out after two nights. I did not dare to test the root tubers, as continuous low temperatures can also cause frostbite, but it is not easy to detect frostbite in root tubers.
So, don't say that plants have no problems at minus 4 degrees Celsius. Brief periods of minus 4 degrees Celsius are not a problem, but more than 5 hours of minus 4 degrees Celsius, especially on the shady side, can make it difficult for succulents to avoid frostbite. On the sunny side, sometimes due to environmental factors, such as walls or potting soil that can absorb heat during the day and slowly release it at night, the actual duration of low temperatures is not long and the impact on plants is not too great. However, if there is nothing to store heat during the day, the continuous low temperature at night can easily cause frostbite. Without heat storage, the environmental temperature will remain low for a long time, which is the difference between shady and sunny sides. Ground-planted plants and plants on balconies will have different degrees of cold tolerance in the same environment, as the earth can release heat, while balconies cannot maintain heat for a long time. Understanding the relationship between low temperatures and plants superficially, I believe that many flower enthusiasts will also combine their own environment to take care of their plants well. Based on their own conditions, they should correctly care for their plants, so do not copy others' methods mechanically and be flexible.
The detailed explanation of the issues related to the cold tolerance of succulent plants shared above is for reference only!