The Blackthorn Winter is a spell of cold weather in early April which often coincides with the blossoming of the blackthorn in hedgerows. The pure white flowers of the blackthorn, which appears before the leaves, matches the snow or hoar frost covering the fields nearby.
It is the first tree of the year to come into bloom in February or March, depending on the winter. The white flowers appear on the dark brown twigs before the small, toothed and oval shaped leaves. The Blackthorn has very sharp spines covering the branches which defend it from grazing animals. The fruit of the Blackthorn, known as sloes, are bitter to the taste and are used in the making of sloe gin. They are usually ready to pick in October when they are a blue, black colour and often covered in a white powdery bloom, which is a yeast fungus. Botanically the Blackthorn is a small plum tree and suckers from the main tree develop a dense thicket.