I'm a novice gardener. I put a load of mambrane down with conifer chippings on top about 18 months ago. Now I have extensive weed growth in the chippings. They are easy to pull out, but it's a pain. In places where the chippings got moved aside, the membrane disintegrated in the sun.
Others will be able to offer better advice but I can say that some membranes are better than others, we need to find a sun resistant one. Also (our garden is steeply sloping too), the chippings may just slide into a heap at the bottom of the slope.
I'd be very interested to hear what others have to say as I need to do something with a large patch of steeply sloping ground, and was just wondering about planting fruit trees and giving the ground under them the odd strim to deter (currently prolific) weeds. How do you encourage grass rather than weeds? Would membrane/woodchip be better. I've been using a lot of glyphosate to get the area under control, but maybe that would damage trees.