Can Acorus calamus tolerate low temperatures? An analysis of its winter cold hardiness
Winter has already arrived, and especially recently the temperature has been persistently low. For enthusiasts who like growing Acorus calamus in pots, this is certainly not good news. Many people worry, and rightly so, that with the recent weather continuing to drop, if you still do not know whether Acorus calamus can withstand such a continuous stretch of low-temperature weather, then it is necessary to read this article carefully.
As for how cold-hardy Acorus calamus is in winter, this depends on whether it is wild or artificially grown indoors. Take Acorus tatarinowii (grassleaf sweetflag) for example: if it has always grown in the wild, then even if the winter temperature drops below 0°C, it generally will not suffer frost damage or freeze to death. But if it is Acorus tatarinowii grown artificially indoors in pots, its ability to withstand the cold is very poor, and when it encounters continuous low-temperature weather, it is very prone to cold damage. At first, yellowing leaves appear; if ignored, it will then show signs of withering.
At the same time, different varieties of Acorus calamus also differ in cold hardiness. Here, we need to understand Acorus calamus (sweet flag) and Acorus tatarinowii (grassleaf sweetflag) separately.
Generally, the cold hardiness of Acorus calamus is relatively poor. In winter, if no artificial measures are taken to keep it warm, its leaves often wither as the temperature gradually drops. However, when the temperature warms up again in spring the following year, the old plant will sprout new shoots, and as long as conditions are suitable, the new shoots tend to grow fairly quickly, with the leaves soon reaching a length of 100 cm. By then, a stretch of fresh green will present itself in a brand-new posture.
As for Acorus tatarinowii, its cold hardiness in winter is slightly stronger than that of Acorus calamus. As long as the temperature can stay above 8°C, its stems and leaves generally will not wither. In southern regions, no deliberate warming measures are usually provided; but in northern regions, because the temperature environment is relatively harsh, warming and cold-protection measures need to be taken in time, otherwise it will quickly wither as the temperature drops.
As for warming measures for Acorus calamus bonsai, you can choose to put the small pot inside a larger pot, then move both the large and small pots together to a relatively warm place indoors, thereby reducing the risk of cold damage. As for the potting soil, it is only necessary to keep the soil with a certain amount of moisture; do not let it become too wet, but rather keep it in a slightly dry state. Moreover, the watering frequency should be decided according to the dry or wet state of the potting soil, and it is advisable to replenish water when the daytime temperature is relatively high. Of course, in winter you should also avoid prolonged direct sunlight, otherwise the risk of overwintering will increase.