https://en.wikipedia.org/wiki/May_Day
In the Rhineland, 1 May is also celebrated by the delivery of a maypole, a tree covered in streamers to the house of a girl the night before. The tree is typically from a love interest, though a tree wrapped only in white streamers is a sign of dislike. Women usually place roses or rice in the form of a heart at the house of their beloved one. It is common to stick the heart to a window or place it in front of the doormat. In leap years, it is the responsibility of the women to place the maypole. All the action is usually done secretly and it is an individual's choice whether to give a hint of their identity or stay anonymous.
In Italy it is called Calendimaggio or cantar maggio a seasonal feast held to celebrate the arrival of spring. The event takes its name from the period in which it takes place, that is, the beginning of May, from the Latin calenda maia. The Calendimaggio is a tradition still alive today in many regions of Italy as an allegory of the return to life and rebirth: among these Piedmont, Liguria, Lombardy, Emilia-Romagna (for example, is celebrated in the area of the Quattro Province or Piacenza, Pavia, Alessandria and Genoa), Tuscany and Umbria. This magical-propitiatory ritual is often performed during an almsgiving in which, in exchange for gifts (traditionally eggs, wine, food or sweets), the Maggi (or maggerini) sing auspicious verses to the inhabitants of the houses they visit. Throughout the Italian peninsula these Il Maggio couplets are very diverse—most are love songs with a strong romantic theme, that young people sang to celebrate the arrival of spring. Symbols of spring revival are the trees (alder, golden rain) and flowers (violets, roses), mentioned in the verses of the songs, and with which the maggerini adorn themselves. In particular the plant alder, which grows along the rivers, is considered the symbol of life and that's why it is often present in the ritual.