I recently "inherited" a garden from my grandmother as she is becoming too old to garden regularly.
It's a lovely garden as it's huge and the whole garden is styled like a raised bed with dirt that was brought in a year ago (which is coveted in my area due to poor rocky soil). The whole garden gets about 6-8 hours of sunlight and not too much wind. The soil has been tilled but was otherwise kept organic
My problem is that about two thirds of the garden are covered in dead, overgrown raspberry bushes that no longer produce but have been coming up for years no matter how many times they are cut down. My grandma formerly gardened in the front third of the garden with a thick mound of mulch preventing the raspberries from spreading any further because she was afraid of them. I've already planted a dwarf fruit tree in the back of the garden and I plan to let the raspberries grow freely around the fruit tree with some pruning to hopefully coax them into being productive again, but I'd really like to plant some other stuff in the rest of the garden. Any advice on how to kill these things? I've tried smothering them with mulch and cardboard but a few strong ones still come up even through all that and they're just everywhere. At this point could I just plant the three sisters garden on top of the remaining raspberries and hope for the best?
My goal for this garden is to have a food forest/wind barrier (trees and raspberry bushes but also a row of serviceberry bushes spaced a bit away) in the back third, a three sisters squash garden in the middle third where I can't get rid of the raspberries and an asparagus and strawberry polyculture/salad greens area in the front third.
