Left: The powerful but beneficent vervain (Verbena officinalis) growing in the bed devoted to Plants Used in Medieval Magic in Bonnefont Cloister Herb Garden; Right: Seed capsules of the sinister and poisonous thornapple (Datura metel) growing nearby.
Trefoil, vervain, John’s-wort, dill,
Hinders witches of their will,
Weel is them, that weel may
Fast upon Saint Andrew’s day.
—Traditional rhyme, put into the mouth of the gypsy Meg Merrilies by Sir Walter Scott in Guy Mannering.
Medieval calendar practices, and the plants associated with them, were an amalgam of Greco-Roman and Celto-Germanic observances with Christian beliefs and traditions. Many folk rites performed at the thresholds between the seasons of the year were intended to avert storms, ward off diseases of cattle, and prevent the blighting of crops. All these misfortunes were attributed to the activities of witches. The bonfires and charms associated with May Eve (the night before the feast of St. Walpurga) and Midsummer’s Eve on June 23 (the eve of the feast of St. John the Baptist) were intended to deflect such catastrophes, and to cope with the increased activities of fairies, ghosts, and witches who were abroad and especially active at those times. These periods were also believed to be propitious for divination, especially to determine who might love or marry, or who might sicken and die, in the coming year. Plants often played a role in these prognostications.
The practice of mumming or guising (dressing up in costumes) and the custom of asking for food, drink, or alms in exchange for blessings or good will might be associated with any and all of these celebrations, including those which fell between autumn and winter, as did the feasts of All Saints, St. Martin, and St. Andrew in November, or between Christmas and the New Year.
The observance of All Hallows or All Saints Day on the first of November was extended throughout the Church by Pope Gregory IV in the ninth century, although communal feasts in remembrance of all the martyrs were instituted much earlier. The celebration of All Souls Day on November 2 was first established in the tenth century. The commemoration of the dead and the institution of prayers for the faithful departed on that date gradually came to be celebrated by the Church as a whole. These holy days coincided with the autumnal feasts of the dead common to the Germanic and Celtic peoples of pre-Christian Europe. The roots of the modern secular holiday of Halloween are found in Irish and Scottish tradition, and ultimately derive from the ancient feast of Samhain.
We now associate witches, goblins, and ghosts primarily with Halloween, but this was not the case in the Middle Ages, nor do I know of any medieval magical plants specifically associated with autumnal feasts, as they were with spring and summer festivals. However, many species were used in both white and black magic throughout the calendar year.
The bed devoted to magical plants in Bonnefont Cloister Herb Garden includes both plants used in witchcraft, like the sinister Datura metel, and protective plants, like the vervain used as an amulet against the activities of witches, demons, and fairies. The same herb is sometimes said to be both useful to witches and powerful against them—the power is in the plant, and can be used by whoever possesses it.
More on plants used in medieval magic to come . . .