I was coming to this forum to post more-or-less the same question! We have some steep sections in our front
yard that are a headache to mow (or rather, weedwack, it's too steep for our mower....or rather, eventually I'd like to be good
enough on my scythe to just scythe them down). I actually pulled up a bunch of creeping juniper from some of these steep sections that was planted years ago, and sprinkled lots of white and crimson clover seed (also we planted a bunch of
apple trees here, the main reason for pulling up the creeping juniper) But other steep sections that were just grass, I have basically just let grow all summer, and only mow them down once a year.. This seems to be working because, in addition to grass, there is plenty of golden rod, joe pye weed, and other good stuff for pollinators. There are some plants i'm concerned about latching on in these sections, though. Mostly multi-flora
rose, which is a big problem around here; and box elders that seem to want to grow anywhere. So I go through and dig those out if I see them. I'm thinking that if you just let the grass grow all year in certain sections, and mow down once in early spring, you'll get some good other
native plants establishing themselves with minimal other effort....but if anyone else has differing strategies, please let me know