What are the 2 meanings of "is yon wreath of roses a garland to hang above our graves" in Hawthornes, The MayPole of Merry Mount?

The hanging of a garland upon the maypole was considered the mark of a happy colony yet the girl (Edith) with the garland looks so sad.The speaker wonders if the garland is meant for a grave instead. This would certainly be auspicious but not in a happy way as the garland on the maypole.