I have that same problem (who doesn't eh?) and unfortunately the ones in my yard are doing great. They don't get the full day's sun like that berry farm did tho

I have that same problem (who doesn't eh?) and unfortunately the ones in my yard are doing great. They don't get the full day's sun like that berry farm did though. I pull them out from the roots and every year they come back. It's right along the fence line too, which makes it very difficult to maneuver for pulling them out. I have snooty neighbors that get uppity about dandelions growing in my yard. I love blackberries and sometimes I just want to let them grow, but my neighbors would have a heart attack and sue me for it given the chance hah.