Blackthorn Weatherforecasting

Blackthorn Blossom

For the past two weeks, almost since the March equinox, the Blackthorn has been increasingly floriforous around here. It is a ghostly presence in the hedges, with its white flowers growing along the smaller branches and tops of Prunus spinosa trees, leaving their black trunks bare underneath – almost like the child dressing up at Samhain with black leggings and a white sheet over their heads. Yet the hawthorn which makes up the bulk of the hedges around here is now glowing green with fresh young leaves, creating a patchwork effect.

The old saying for this time of year was “Beware the Blackthorn Winter.” With high pressure dominating and the weather having turned beautifully sunny and warm for much of the country, I have felt that Spring has finally sprung – yes there is the occasional nightly frost, but nothing particularly long lasting since most days it has gone within an hour of sunrise. So I have been puzzled as to why Blackthorn blossom should suggest a return to winter, and decided to investigate further.

Patchwork of white Blackthorn and green Hawthorn

It turns out that normally the blackthorn flowers at the middle to end of April – when there is very often an unexpected cold period. This year winter has been mild, and the weather seems to be continuing that way, so I am thinking this has caused the blackthorn to be particularly early. It is not alone; bluebells have been flowering since the beginning of April around here, 3-4 weeks earlier than normal. But the result of this is that the Blackthorn is not coinciding with a cold spell as it usually does; MET office forecasts are currently predicting ‘rain or showers, turning wintery’ ie snow for next weekend…

I now await confirmation from another tree for my planting out, using that other favourite saying “Ne’er cast a clout ’till May be out.” It refers to the hawthorn blossom, which is usually in flower in mid-May around here – and has generally proved a reliable guide to the last frosts (provided I wait for my own hedge to flower rather than those in more sheltered locations). It already has flower buds, but as I have seen before, the tree is happy to keep its flowers in bud if necessary until the cold weather is over. Wise old trees!