Synonyms for Blackthorn: Sloe, Sloe Berry
Scientific Name: Prunus spinosa
The dense, spreading, much-branched thorny shrub, which can reach a height of up to 3 m (9 feet), flowers from March to April. The small white scented flowers appear before the leaves. They are usually solitary, on short stems, but cover the entire length of the branches so densely that the whole shrub is shrouded in white. In May, after the flowers, the oval, tooth-edged leaves appear, and in late summer the bluish-black plum-like fruits which have a whitish bloom and astringent green flesh. They are 1 cm in diameter, contain a stone and are only edible after the frost. The thorns, incidentally, are transformed lateral branchlets.
Blackthorn likes sunny hills and dry, sparse deciduous woods with chalky, deep soil. Together with other members of the rose family it often forms impenetrable thorny thickets. The light-loving blackthorn is extremely resistant to pests and regenerates quickly after cutting. It can colonize shallow soil quickly and spreads through seed dispersal by mammals and birds and by production of root suckers. Even on wind-exposed sites it defies the natural forces. So it is not surprising that it was used as pioneer wood for stabilizing embankments and dry slopes and for landscaping slag heaps and wasteland, as well as for wind and snow screens. With its high value as honey plant, too, blackthorn emerges as something of an ideal shrub. In spite of its fertility, blackthorn has largely disappeared from the agricultural landscape as a result of modern farming methods which made small fields impractical. Only recent ecological research has demonstrated the utility of hedgerows for agriculture and shown that their protection is worthwhile.