Thursday 24 September 2020

May blossom: in September?

Invertebrate surveyor Steve contacted us this week to say "while conducting a scoping survey for invertebrates near Milton in Cambridgeshire yesterday, I came across flowering hawthorn in a hedgerow. It also had berries. I've never seen this phenomenon before: it's crazy!" 

We agreed - hawthorn Crataegus monogyna (and Midland Hawthorn C. laevigata) are also known collectively as May blossom, because that's when they usually flower - they aren't  known as September blossom! But Steve's photos (on right and below left) clearly show both flowers and fruits on the same tree.

We often hear reports these days of plants blooming at unexpected times - our annual New Year Plant Hunt is testament to that. Sometimes we're looking at species known to have a second flowering, e.g. Common Dog-violets bloom in spring, around the Spring Equinox, but they often bloom again in September. 

Hawthorns are a different matter though. We've had occasional reports in recent years of autumn-blooming hawthorns, but very few. So, is this a rare occurrence? Is it linked to climate change? Or is this a phenomenon that occurs regularly in the autumn and it's just that few of us have noticed it before? Or if we did notice it, we didn't tell anyone?

Let us know if you're spotting hawthorn blooming this month, or if you have noticed any other examples of unseasonal blooming. And if you're out surveying for invertebrates, birds, mammals, fungi... don't forget to take a good look at any plants you see on your travels - and vice versa: botanists who spot unusual fauna will find the relevant recording societies keen to hear from them. Check out this list of recording schemes and record what you find!


  1. I spotted Midland Hawthorn in flower with fruits yesterday, 1st Oct, in TQ52,83, Hornchurch Country park. I have taken photos as it was such a surprise but have not yet told my County Recorder! The Hawthorn was growing next to a Salix viminalis that had catkins in flower in September and I have flowers of that too. Is there anywhere I should be sending this information.

    1. Sounds like you're already in touch with your County Recorder so it would be worth notifying him/ her about your finds. Do you know about Nature's Calendar? You could also log your observation with them:

  2. My Pear tree blossomed in September, double take on that. Bedford.

  3. I was astonished to see a Hawthorn tree with blossoms and berries today in Mabley Green Hackney in London.

  4. Well, there is a 'very rare' variety of Common Hawthorn (C. monogyna 'Biflora') that flowers twice a year, once as usual in spring and again in mid-winter if it's a mild winter. It's called Glastonbury Hawthorn, and is ascribed to the visit by Joseph of Arimathea to Somerset (soon after the cruxifiction, when he established the first Christian church in this country, the start of 'Celtic Christianity', long before Catholicism), when he inserted his 'whitethorn' staff into the ground and it miraculously flowered at Christmas time! Perhaps this variety is a bit more widespread than we thought, or perhaps there are recessive genes in the general population that cause such bi-flowering every now and then. September is very early though (it's seldomly before the New Year and the worst of winter is over, apparently). And how to explain the flowering and berries ? Well, if the second 'winter' flowering starts early, then that would cause an over-lap in the 2 flowering seasons, giving flowers + berries at the same time. Gundula

  5. October 2nd 2023 and my hawthorn tree is starting to get blossom - how strange


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