Some years ago I planted 2 small blackberry shoots along the rear
fence of my yard. While I love the blackberries I get, I now have
plants and they are migrating forward into my yard. Last year I dug
and removed the plants that had come too far forward from the fence.
My goal is to do something permanent to keep the grass out of the
blackberry area and the blackberries out of the grass.
My idea is to dig a narrow trench (30 to 40 feet long) parallel to
a few feet away from the fence (basically an arms length away) and
bury something like alumninum that is sold in rolls of various widths
to prevent the roots from migrating across that border, then maybe
later putting down rock inside the border.
1) How deep does material need to go? I am guessing 6 to 8 inches or
will the roots eventually go deeper and come under? I would like
solution to last 20 years or more.
2) If I put some rock down where the blackberries are will I kill
off accidentally? I want to keep the blackberries, just contain them
and have an area that still looks reasonably attractive in the winter
when the canes have been pruned back to the ground. I am guessing a
thin layer of small landscape rock might be okay or should I go with
3) If the alumnium is a bad idea, why, and what would you suggest
Thanks in advance for any and all help or humor.