Blackthorn (Prunus spinosa)

This was a species I was very excited to come across for the first time when I moved to the UK, as it wasn’t present where I grew up in Ontario. I find it impressive at every stage of its growth, from the explosion of white blossom in spring, the jewel-like sloe plums that ripen through the summer and autumn, and the brooding black and densely thorny thickets that make it unmistakable in winter. I have eaten the fruits fresh and ripe off the bush, though one must be prepared for the intense drying quality they have on the tongue that goes along with their sharp flavour. Part of my acculturation in the UK has been to adopt the tradition of sloe liquor making in late autumn, and to understand that really good patches of sloes will have families that consider them ‘territory’ - woe be it to the hapless forager who beats them to it!

What it looks like

Blackthorn, or Sloe Plum, grow in dense growths of shrubby bush about 3-7m tall. The bark is dark and sparsely equipped with thorns about an inch long or longer. It’s very ‘twiggy’, with the plums nestled inside the shrub sufficiently to force you to navigate through the thorns to get them. Leaves are narrow and finely toothed, and blue-green, making this shrub easy to spot at a distance in comparison to other hedgerow standards. In spring, blackthorn is covered in clusters of tiny, delicate white flowers with a sweetish scent. The plums grow singly or in sparse clusters, beginning green and ripening to a rich blue-black with a brilliant blue bloom on them, roughly 1-1.5cm in diameter. The fruits are intensely flavoured and bitter, and will dry your mouth. The pit fills roughly half the volume of the fruit. It is not a raw eating plum.

Uses

For harvesting, tradition has it that you wait until after the first frost, but by then you’ll find that most of them have been picked. September through November is your window. Colder weather will concentrate the sugars in the fruit, resulting in a better flavour. If they freeze, they will also release their juices more willingly when infusing gin or another alcohol of your choice, so why not pop them in the freezer overnight before trying? Sloes can also be made into jam and jelly. The wood of Blackthorn is good for making tools and walking sticks, the grain being quite straight. It also burns well, so look for dead standing blackthorn on your rambles to tuck into your fuel bundle for when you want a small fire, such as when using a twig stove.