Although it’s been fairly cold recently, spring is definitely on the way. Some of our trees are already in bloom on the Common and at the Leg o’Mutton Nature Reserve. If you’ve spotted the white petals, you may have come across a flowering Cherry Plum or Blackthorn tree. Here is how to tell them apart.

The earlier blooming of the two is the Cherry Plum (Prunus cerasifera) a small tree with white blossoms appearing in late winter – early spring. We have both the standard and the pink variety which has purplish leaves rather than green, and pale pink blossoms instead of white. The fruits are yellow, orange or red plums, much loved by birds.

Blackthorn (Prunus spinosa) flowers a few weeks after Cherry Plum, in early spring. Its flowers are white and very similar to Cherry Plum flowers. It’s easy to distinguish the two however, if you look at the back of the flower, where you can see the small green sepals behind the petals. The sepals of the Cherry Plum are ‘reflexed’, bent backwards, pointing away from the petals. By contrast, the sepals of the Blackthorn follow the curve of the petals, they are not reflexed. Blackthorn bears small, dark blue berries, called sloes, that are much smaller than a plum or even a cherry. They are approximately 1cm across and very acidic in taste.

The leaves of Blackthorn and Cherry Plum are very similar, and they all appear after the flowers have opened. Both trees are thorny but Blackthorn more so, hence its English and Latin names. Blackthorn is an important food plant for larvae of the Black Hairstreak, Black-veined White and Brown Hairstreak butterflies.