Back in 2008 February was so warm and mild that by the start of March Blackthorn was already in blossom. In the hedgerows and usually towards the end of the March the blackthorn (also known as sloe) flowers. Bushes are covered in clouds of white blossom borne on its dark, thorn laden branches. This shrub is sometimes confused with hawthorn, but the hawthorn does not flower until May and comes into leaf before the blossom opens.
The Blackthorn is a member of the genus Prunus, which includes many fruit trees including cherry, plum, damson, apricot, peach and almond. To call Blackthorn a tree may be misleading, it is actually a large shrub which grows to about 12ft, with a rough, black bark and dark twisted branches bearing long, sharp thorns. Usually planted as part of a hedgerow it tends to develop into a tangled, twiggy, almost impenetrable thicket. favoured by nesting birds because of the protection it provides and can be found growing as part of the hedgerow along many stretches of the Blackwater Valley Path.
The small delicate flowers are usually white but occasionally pink with red-tipped stamens, and the oval leaves are small and dull green, turning yellow in autumn before they fall. The shrub bears dark-blue almost black globular fruits known as Sloes, which ripen and sweeten after the first frost. Eaten by birds they are also picked by man to make jam or wine and to flavour Gin. This berry has been found in archaeological sites from the Mesolithic and Iron Age periods (8,000-2,700 BC), proving that it was a part of early man’s diet. Sloe berry juice can also be used as an ink or strong red dye.
Blackthorn is valuable to wildlife and is a great favourite with nesting birds. Some 109 identified insects species have been associated with it, including the Brown Hairstreak butterfly, which lays its eggs low down on the twigs where they remain over winter. The emerging caterpillar remains amongst the leaves feeding until it pupates in June.