Q. How did May become the month dedicated to the Blessed Mother?
A. Here’s a reply from Father Reginald Martin:
The liturgical season honoring Mary is Advent, when the Church (like Mary) prepares for the birth of Jesus. Popular devotion, however, associates October and May with Mary as well. Mary’s connection to October is easy to grasp; Oct. 7 is the feast of the Holy Rosary, the anniversary of the 1571 Battle of Lepanto.
Mary’s link to May is somewhat more complex. May is the month our Greek and Roman forebears associated with birth and new life. In Northern Europe, especially Rhineland Germany, a series of poor harvests in the early 18th century prompted Catholics to offer special prayers in May for good weather, and to protect blossoms so they might bear fruit. A connection between Mary and fruitful new life — with floral decorations — would be quite natural.
In mid-18th-century Italy, private Marian devotions became public springtime services when bishops promoted them to distract the faithful from boisterous university student revels. These devotions became a fixture in France, where Jesuit Pierre Dore popularized them.
The dogma of the Immaculate Conception was defined in 1854, but we read it was not announced in many dioceses until the following year — during Marian May celebrations. This helped cement May as Mary’s month.