CyndiSmith I have used mineral mulches, principally pea gravel and “buckshot” plus coarse (between 3-7mm) sand , for many years on perennial plantings. It works great and if you leave or make space, makes good home for ground nesting bees and such. That practice, mineral mulch, seems to be having a bloom time all over the place now and that, in my view, is a good thing. Currently I don’t know many in this part of the world who are advocating, apart from rock and crevice gardeners, but Claudia West and Thomas Rainer give some time to it in their book Planting in a Post Wild World but the main proponents are James Hitchmough, Peter Korn, Nigel Dunnett and John Little and others over across the way including Jo McKerr who has an amazing garden and you can find webinars with her. Many great examples of why it works for low fertility meadows. John Little is a particular favorite of mine currently as he is promoting the use of reclaimed mineral components which opens up a whole other part of the conversation: reuse of industrial waste for insect habitat creation. This does have a place in rural spaces, not just post industrial… we are post agricultural and full of waste areas that are gravelly. Yes the “weed and grass intrusion” is a challenge. This is a real part of the low fertility conversation, including parasitic plants (paint brushes, yellow rattle, etc) , and mineral, weed-free mulches.. forage grasses like high fertility. I long for the moment when agencies will include, or at least acknowledge, introduced forage grasses (not just canary grass!) on weed lists: until that day I cannot call introduced nectar producing or (native) caterpillar feeding forbs weeds or look at our pastures, filled with introduced plants feeding introduced ungulates, and call it good. Why are they good and not the little plants feeding the little animals we all love and put on T shirts? hmmmm..
sorry, a soapbox. I suppose one big question is, are we trying to create meadows where meadows might have actually been? Or are those spaces so profoundly changed by being pastures with those introduced forage grasses and ungulates for so long that creating a “native” meadow ecology too difficult? I don’t know and would love to hear other ideas… but taking the first layer of grasses and soil away works pretty well! it is just a question of fuel use vs benefit. I think of this a lot also in terms of what it takes to produce, transport the various materials: cardboard, plastic, road fabric, gravel, etc.. plus the machine time to prepare, remove, and place these things. One thing I think is good about mineral mulches is that they are enduring, add no organic matter or fertility to the soil, are weed free…. so much to learn. would be so cool to get together in a space one day and share together.