The first day of the “petrivka” (St. Peter’s Lent) is an important point in the Ukrainian traditional calendar. This day does not have a fixed date and varies depending on Easter each year. It is a marker of the transition from the season of spring to the season of summer. Transitional moments of the calendar are endowed with semiotic meanings in traditional culture. Heterogeneous rituals are dedicated to this day in Ukraine. They have different forms in different regions, have different semantics and perform different functions. Women’s erotic and rain-making rituals were designed to ensure the fertility of the fields, ritual games were intended to protect poultry from attacks by birds of prey, and the ritual exorcism of demonic temporal demons (rusalky) marked the end of the spring season. Commemoration of the dead and unborn children is an important part of the rituals of this day. A whole complex of rituals is preserved in the northwestern Black Sea region to this day. These rites are connected with the Moldavian holiday complex “jarba verdi” in the west of Odessa region. The analysis of forms and functions, the current state of the Ukrainian and Moldovan versions of the “green grass” and “jarba verdi” celebrations will provide an opportunity to investigate the influences and interferences of different cultures in the places of their contact.