Sloe Berries: Transformation, Protection & Celtic Reverence Step into the mystical realm of sloe berries, the small yet powerful fruit of the blackthorn shrub (Prunus spinosa). Long celebrated in European folklore—especially within Celtic traditions—sloe berries are believed to carry profound spiritual energies that encourage personal growth, protection, and inner resilience. Symbol of Protective Energy • Nature’s Guardian: Sloe berries have often been used in charms and talismans to ward off negativity. In folk practices, placing a sprig of blackthorn or dried sloe berries near entryways or on altars is thought to create a protective barrier.