Blackberry Week

As a kid growing up in the north-east of England in the 1970s, the half-term school holiday that occurred early in October was always referred to as “Blackberry Week”.  A quick on-line search suggests that the phrase goes back to at least the 1930s (can anyone trace it earlier than this?) and it refers to the time when blackberries (Rubus fruticosus agg.) were ready for picking.  The local kids would spend hours at our favourite blackberry patches, picking bags full of dark, luscious berries to take home for our mothers to cook into pies and crumbles, or stewed to eat with cream. As much fruit was scoffed as was collected (“one for the bag, one for me, one for the bag, one for me…”) and over-ripe ones were pelted at one another until we looked like road casualties.

All of this has been brought to mind recently, since we began to pick blackberries in our garden – at the end of July.  That’s at least two months earlier than I recall doing as a youngster.  Part of this difference can be attributed to latitude; I now live more than 200 miles further south than I did, with a concomitant advance in relative dates of flowering and fruiting, amongst other phenological indicators.  But that can’t be the only answer, the difference is too extreme, though I have not (and I doubt if anyone has) assessed it systematically.

The main reason for the difference, it seems to me, is that our seasons are shifting. We know that spring is generally earlier now in the UK than it was 20 years ago, and with that shift, autumn has likewise been brought forward and is lasting longer, as shown by changes in fungi fruiting patterns.  There’s a lot of research interest in these changes, for example the Centre for Ecology and Hydrology’s collaborative project.  Whilst phenology scientists usually express these changes quantitatively, as number of days difference between events, such as bird migration dates or plant flower times, across a period of years, any person with an interest in the natural world can see these changes for themselves, even in gardens.

Without realising it, as kids we were also making decisions about where to pick blackberries that go directly to the heart of biodiversity, which is essentially about variation and difference in the natural world.  As part of our own knowledge of the local (and very personal) biodiversity of the area in which we played and explored, we would know the best bushes from which to pick fruit, and the ones to avoid because the plants produced berries that were small, or had a poor flavour. Blackberries are hugely variable in all manner of ways, including leaf shape, number and size of prickles, flower size and colour and, most importantly for us, characteristics of fruit quality.

Much of this variation is genetic rather than environmental and reflects the complex biology of the species, or should I say group of species. Let’s go back to the scientific name of blackberries: Rubus fruticosus agg.  I’ve posted in the past about the formalities of writing scientific names of species, and the “agg.” element is an unusual addition not often seen.  It’s an abbreviation of “aggregate”, which in its taxonomic sense means a collection of species that are very similar to, and may even be synonymous with, that species.  The plant that we know and love as the blackberry is actually an aggregate of many hundreds of “microspecies”, at least according to some plant taxonomists.  This is because of the variable sexual behaviour of blackberries and their tendency to hybridise.

Blackberries are often taken for granted and dismissed as invasive woodland dominators that need to be kept in check.  But they are important for their cultural significance, have a fascinating biology, attract a wide range of insects to their flowers, and provide both fruit and habitat for birds and mammals.  Blackberries are worth making space for if your garden is large enough.