I have both tame and wild blackberry plants. All the wild ones produced nothing this year because of drought. And I keep forgetting to tend the tame ones, so they didn't produce anything either. I really shouldn't have planted them behind the chicken house. I always forget they are even there, much less that I should weed and water them.
I did plant some new blackberry plants in my main vegetable garden this year. The squash plants overran them, though. They are still there, but not doing as well as they should have by now. It's hard to prioritize a perennial that will bear fruit in a year or two over a squash plant that is producing squashes NOW.
I'll know to give the squashes a lot more room next time.