Blackthorn is very thorny. It makes a good hedgerow plant (together with hawthorn, gorse and holly) as it creates impenetrable thickets and therefore provides good protection for a whole range of wildlife. Many plants grow beneath it as they are protected there from grazing animals. Birds build their nests among its branches and small mammals like hedgehogs find safe shelter below its dense canopy.
The leaves are small and alternate. They are dull and sometimes sticky above and hairy on the veins beneath.
The leaves open after the flowers.
The white flowers have 5 petals. The flowers are white and appear very early in the spring before the shoots. They are one of the first sources of nectar and pollen in the spring.
The fruits, called sloes, are bluish-black drupes, often with a waxy coating. The fruit is round, between 1 and 1.5cm long, and contains one large stone and, normally, not much flesh.
They are rich in vitamin C, but very sour to taste. They sometimes sweeten after the first frost and remain for a long time on the plant – good winter food for birds and mammals.
When the plant is old then the bark becomes very dark – almost black – and the timber is very hard.
Blackthorn grows in hedges, on rocks and in woodland. As a shrub it grows up to 3m in height.
It thrives in full sun and grows in all kinds of soil, although it prefers a soil rich in lime. The only soil it doesn’t like is very acid – like peat, where it will not grow.
Blackthorn protects soil from erosion and is used as a barrier against the wind.