St. John’s wort (Hypericum perforatum) is a perennial plant indigenous to Europe. It is named for its tendency to flower and be harvested around the 24th of June which is St. John’s day. Traditionally the plant was used to ward off evil – it was hung over religious icons round the house on St. John’s day.

Whilst the St. John’s wort plant is seen by many as beautiful and graces many ornamental gardens, it is also viewed as a noxious weed that is toxic in pasture land in many countries where it has been introduced.