I built one back when I lived in California during fire season, and then again during the pandemic. They do such a nice job making the air less gross.

I think that’s about what mine looked like after 3 or 4 weeks too…

I was coming here to say that! It’s possibly apocryphal, but the way I heard it was that the University of Illinois at Urbana Champaign did this when they did their main quad (I still remember them telling me this when I got a tour before applying there 30 years ago). And they didn’t just look for where the plants were dead, but they also looked for broadleaf weeds, which sustain trampling better than grasses (it’s a land grant university in the midwest. Of course there’s an agriculture angle).

I’m working on it too. I’m part way there. (47 year old telecommuting engineer and off grid homesteader hoping to retire to do farm stuff full time as soon as I can)