I am lucky to have a large garden,where blackberries can be picked from several places among the hedgerow,and the do not invade the lawn/garden etc.
I was so impressed,I have planted a couple of the the variety Black Butte,onto trellis for future pickings.
This variety grow to huge sizes.
Gardeners' World Web User
I have just got a blackberry bush. and i have put it on my allotment. so that the kids come in to the allotment next year and pick the berrys just like when we were kids. and pick the berrys from the hedgerows or along side the railway tracks.or out the woods. its something you dont see nowadays