Posted: 08/10/2012 at 13:41
Yes, I agree it would be a bit of a waste of space on an allotment, as it can become a straggly, messy bush. And I've noticed that there always seems to be a lot more blackthorn blossom than eventual sloe fruits, suggesting that many of the bushes don't get as far as bearing fruit some years.
Some allotment sites don't permit the planting of trees, presumably because they might cast shade on other plots, and possibly create problems with root disturbance to paths, beds, etc.
If you do manage to take a successful cutting, perhaps there's an area of hedge on the edge of the allotment site where you could plant it?