No, not for farmers, although I'm sure they are if you happen to be the UK's largest supplier to the crumble industry.
To start off there's the whole what do you call them thing. Turns out that if there's one sure way to prove I'm not from round here it's calling them blackberries in the first place. Och no. In this neck of the hedgerow they're brambles. How that separates them from the plant on which they grow I don't know, although as I don't have a different word for a raspberry bush or an apple tree, some might argue my insistence on calling the twigs and leaves a bramble and the fruit a blackberry is somewhat indefensible.
Nonetheless I am sticking to it, and doubtless will meet fierce resistance from my children in years to come. But then they think the fat man who comes down the chimney is called Santa, so clearly they know nothing.
Anyway none of that matters, because the important thing is not what you call them it's where you find them.
And having found them whose patch is it?
Because it turns out that blackberrying (brambling?) is a little known and under-reported turf war, rife with bitterness and controversy.
I should have known. I should have realised last year when we were in the Lakes. We went for a nice walk along a country lane. There were blackberries, lots and lots and lots. We were seen nibbling on one or two by a very pleasant, very smiley, elderly gentleman standing on his front doorstep as we went by. We went back a day later to find nary a blackberry in sight. Hedges denuded of all but the slightly hairy green ones that even I won't turn into jam. And though I didn't see him at it I just know he was out there in the rain the night before defending his patch...
I've asked around and it's not just in Cumbria that people get proprietorial about their tangle of thorns, wasps and fruit. Oh no! say friends who live up rural lanes. Those are OUR brambles. (They're locals. You can tell). I can come and take some when invited, I'm told, but not too many and only under close supervision.
So now I've got a problem. Because I'm new here (still. ish). And we live in a town. So I haven't got a patch. And I want one. And (here's the secret) I've found one. Heavy with fruit and more ripening every day. I've got ice cream tubs full in the freezer and I'm going to go off and get more tomorrow; hiding in the hedge every time a car goes past so as not to make eye-contact.
And no. I'm not telling you where it is. It's mine. As long as no-one catches me.