Since the end of the 19th century, systematic meteorological, astronomical and agricultural observations have indicated the cyclical occurrence of a sudden influx of cold polar air in our geographical region in mid-May. This phenomenon, often characterised by frosts, was well known to farmers and rural residents, who identified the period from 1 to 20 May—particularly the days from 12 to 15 May—as a time requiring increased caution. This tradition-rooted belief in May cold snaps, commonly known as the “cold gardeners”, was an important part of planning fieldwork and protecting crops.
Although May is commonly associated with the height of spring, sunny weather and gradually rising temperatures, meteorological observations indicate that sudden temperature drops occur regularly. This phenomenon is reflected in folk tradition, specifically in the names “cold gardeners” and “Cold Zosia”, referring to a specific period in mid-May.
Three saints—Pankracy (12 May), Serwacy (13 May) and Bonifacy (14 May)—symbolise the days on which the likelihood of frosts, often severe, is particularly high. This phenomenon is completed by “Cold Zosia” (15 May), Zofia’s name day, after which, according to tradition, the risk of spring frosts should decrease significantly.
Although science does not confirm an absolute link between these dates and temperatures, this tradition remains extremely important to gardeners and farmers. Understanding and respecting the phenomenon of the “cold gardeners” and “Cold Zosia” makes it possible to take appropriate precautions to protect delicate plants from the harmful effects of spring frosts and thereby safeguard future harvests. Therefore, despite the optimism of spring, it is sensible to remain vigilant in May so as not to be caught off guard by changeable weather.