A series following the 72 British mini-seasons of Nature’s Calendar by Kiera Chapman, Lulah Ellender, Rowan Jaines and Rebecca Warren. 

“Well, Bug Woman”, I hear my East Finchley readers saying, “You must be living in a different ecological niche from the rest of us, because where I live it hasn’t stopped raining for a week”. And you would be 100% correct – the photo above is from a cold snap in December last year. But nothing illustrates the difference between the north and south of the British Isles better than the dates of the first frosts: the average first frost in Aviemore happens between 1st and 10th October, Edinburgh has to wait until between 21st and 31st October, and Barnet (where I live) usually doesn’t get frost until the early new year, between 1st and 10th January. I am more than amused to discover that frost is rare in  Westminster. My head tells me that it’s probably because of the urban heat island effect (whereby cities retain heat in all that concrete and brick) but my heart wonders if it’s all the hot air. You can find out the dates for your area in the UK in this very useful map here.

It isn’t just a matter of north or south though: frost is quite a temperamental animal. If you have a look at the map, you’ll see that early first frosts occur most often well inland, away from cities (that heat island effect that I mentioned above) and come later on the west side of the country than the east side. The west of the UK is traditionally warmer than the east side anyhow (all those Scandinavian breezes blow in not only waxwings (hopefully, it looks like a very good year for these occasional migrants) but cold winds. Of course, everything is up for grabs with climate change, so it will be interesting to see how this winter plays out. Already we’ve seen three storms, with major flooding impacts in the north and east of England, many parts of Northern Ireland and parts of Scotland. But as yet, in East Finchley at least, no frost.

As we know, frost wilts and kills plants, and freezes water so that it’s inaccessible to birds and other animals. Most insects and invertebrates are either hibernating, hiding or dead. It’s a time to remember to supply water and protein and fat-rich food for birds. But there are also benefits to frost – it kills off many pest species of insect, which keeps their numbers under some sort of control, and it’s said to make all the difference to the flavour of parsnips.

In her piece on frosts, Lulah Ellender mentions that frost makes rosehips and hawthorn berries more palatable to birds. She also mentions that some plants need cold  in order to germinate – the freezing temperatures break down the husk of the seed so that the plant can germinate. This is known as cold stratification, and lots of plants need it: Alys Fowler has an interesting article about it in The Guardian here. The list of plants that apparently rely on cold stratification has me scratching my head a bit, though – lavender is a Mediterranean plant, but apparently needs a dose of frost for the seeds to get going. Help me out here, readers! Have you had stick your seeds in the freezer to get them going? Reveal all!

Acorns, apparently requiring cold stratification

And do let me know your thoughts on frost. Have you had any yet? Do you live somewhere where frost is rarer than hen’s teeth? Are you in the process of getting your geraniums in for the winter? Share all. I’d love to know.