Plant

Blackthorn

Blackthorn is a small, deciduous shrubby tree. It grows best in moist, well drained soils and full sun. It is native to most of Europe, the UK and Western Asia. It is often referred to as "sloe". It has a native lookalike on PEI, Hawthorn (Crataegus spp.). However, blackthorn spines have buds growing along their length while hawthorn does not. Blackthorn also starts producing flowers before its leaves are out, and hawthorn does not.

Identification

Here are some key features that may help to positively identify Blackthorn:

  • Can grow 6-7 m tall
  • Densely branched and spiny
  • Bark is dark brown, smooth
  • Twigs are black-purple and develop into spines
  • Leaves are small, narrow, oval, slightly wrinkled with a toothed edge
  • Leaves are pointed at the tip and tapered at the base
  • Flowers are white, on short stalks, and bloom singularly or in pairs
  • Flowers appear in March and April, before the leaves are out
  • Flowers mature into blue-black fruits, 1 mm across
Image gallery
Blackthorn patch. Photo by David Carmichael.
Blackthorn patch. Photo by David Carmichael.
Blackthorn flowers. Photo by Opiola Jerzy via Wikimedia Commons
Blackthorn flowers. Photo by Opiola Jerzy via Wikimedia Commons
Blackthorn fruit, spines and leaves. By Kristian Peters via Wikimedia Commons
Blackthorn fruit, spines and leaves. By Kristian Peters via Wikimedia Commons
Blackthorn bark. Photo by David Carmichael.
Blackthorn bark. Photo by David Carmichael.
Blackthorn patch. Photo by David Carmichael.
Blackthorn patch. Photo by David Carmichael.
Blackthorn thorn. Photo by David Carmichael.
Blackthorn thorn. Photo by David Carmichael.
Blackthorn twig. Photo by David Carmichael.
Blackthorn twig. Photo by David Carmichael.
Blackthorn twig. Photo by David Carmichael.
Blackthorn twig. Photo by David Carmichael.