I inherited a wild compost pile containing, I believe , 40 years of leaves, dry wood and grass. I already excavated about 15 cu yards of compost out of there. I probably have left about the same amount if not more, but it is mostly either hard to reach or contains too much of additions - sand from the road, ashes of unknown origin or mix of compost and fresh pine needles. Also the pile occupies the steep side of the ravine and if I take it all it will be even more steep. Instead, I made terraces with the leftovers and was planning to plant some hostas and other shade loving plants there… I wish I thought about it first, before I spent time on that work. 1-2’ from the edge of compost pile there are wild blackberries growing. I would expect them in compost, but they are not there. There are also no tree roots from three big pines and maple growing around, and in my experience large trees grow their roots into compost piles with pleasure. Some annual weeds (Chickweed, pigweed) growing on top though and don’t look twisted or distressed. Plants in my beds where I added first 15 cu yards do not show herbicide damage (at least not yet). So I do not think it is herbicide issue. But it should be a reason why blackberries avoid such reach location.