This probably sounds less wacky and it makes fewer leaps:

    "During the first millennium of the Christian era, the feast of the Assumption was of enormous importance to most people, since it marked the crowning point of the agricultural year. ... For many centuries before [farming produced two harvests a year], there was only one harvest a year, and this was reaped in July. The feasts of Lammas (the blessing of the first loaves at the beginning of August) and the Assumption (August 15) therefore marked out the period of harvest festivities, and continued to be celebrated as such even after the harvesting had been moved to slightly later in the year.

    "In Scotland, the Assumption – St. Mary's Day, or Marymass – was the most important of the Marian feasts, and the ritual Lammas bannock (the new bread) would be dedicated to Mary Mother. In some places people would make pilgrimages on August 15 to holy wells dedicated to Our Lady. Mary long retained her association with the crops, and one fifteenth-century German woodcut shows her wearing a robe which is patterned with ears of [wheat]. So the glorious culmination of the Virgin's life was celebrated at the culmination of the farming year." (Sarah Jane Boss, Marian Study Centre, Ushaw College, Durham) from here

I'd love to see that wheaty Mary woodcut.

And for good measure, here's a 'Lammas/Marymass' (or indeed any of the other quarters) Bannock recipe:

Bannock

"Marymas Bannock was originally known as Lammas Bannock.
Lammas Bannock eventually was assimilated into Christianity, and Marymas Bannock was made in honour of the Virgin Mary on the 15th August, the Feast Day of Mary ("Feill Moire" in Scottish.)
The Marymas Bannock would be made from grain gathered that day, and would be cooked over a fire.
The father would take the bannock, break it up, and give a piece to each of his family in order of age. The family would then sing a song to Mary, walking clockwise around the fire.
The ashes from the fire were then scattered in the fields." link