What zone/state are you in Watchnerd?
We have a little hayfield behind our yard and one thing that does compete with the tall grass there is native orange flowered Butterfly Weed (asclepias tuberosa). That might be a good one to try. It's definitely ornamental. We have fescue in our field but also other grasses. It's not a native meadow. There aren't a lot of perennials that can handle that kind of competition.

If you plant butterfly weed, it might need some help in the beginning. I think it would be perfectly fine to kill a little area of grass to give the butterfly weed or some other perennial a chance to get started.

Are there any tall grass areas near you where you can observe to see what's surviving and blooming there?

Hi christie,

I'm in the San Francisco Bay Area, zone 10a.

There are many many meadows up in the foothills within a few miles from where I live. Sadly, very few are purely native anymore. Most are full of invasive species.

I'm probably going to smother some of the fescue later this year and then replant with native plugs, probably Leymus triticoides. I'll need over 100 plugs!