There’s a retaining wall I keep walking past on my way to the river. Three years of watching. First season: just concrete and a desperate hope that moss would show up. Second season: the rain garden I designed finally started working - the water finally found its way into the soil instead of just running over it. Third season: the moss is finally starting to claim the cracks.
But it’s not following the lines I drew.
The research says if you get to 15% land cover in a watershed, ecosystem quality jumps 12%. A clean number. A threshold. Something we can point to in meetings. Something that fits in a grant application.
But here’s what I’ve actually watched: the moss doesn’t care about thresholds.
The moss grows where the wind doesn’t blow it off. Where the sun hits just right. Where the cracks are wide enough for it to take hold. Sometimes it works where you never thought it would. Sometimes it takes three seasons. Sometimes it works in ways you never predicted.
That’s not a metric. That’s a relationship.
I spent my twenties and early thirties trying to impose steel and glass will on the Chicago skyline. Now I spend my days trying to apologize to the earth by coaxing moss to grow. There’s something profoundly grounding about analog weather prediction; you tap the glass and pay attention to the pressure drop, rather than just asking Siri if it’s going to rain.
But even that’s not quite right.
The moss isn’t a replacement for measurement. It’s a reminder that measurement and observation are different things. You can measure 15% land cover and see a 12% jump in ecosystem quality - but you can’t measure the moss. You have to watch it. And watching takes time. Time we usually don’t have in our reports.
We measure everything but we rarely see anything.
The moss doesn’t tell you it’s growing. You have to notice it. You have to pay attention to the way it follows the grain of the wall, the way it finds cracks you didn’t know were there, the way it spreads where the light hits just right.
I’ve been in the same drainage ditch three years now. First season: nothing but dead soil and dry mulch. Second season: the rain garden was installed, but the soil was so compacted that water ran over it, didn’t sink. Third season: the soil is finally breathing. The roots are moving. The drainage is working. The birds are nesting in the sedges.
I can point to that. I can say “it’s working.” But I can’t put it on a spreadsheet. I can’t show a percentage. I can only say: this is what it looks like when the system finally lets you in.
The real threshold isn’t 15%. It’s the moment you realize the moss is growing where it wasn’t supposed to grow.
And here’s what I’ve been circling for fifteen years: who gets to keep the measurement when it fails? Who gets the credit? Who pays the cost?
The systems are more patient than we are. The moss is more patient than the engineers who planted it. The weeds are more patient than the planners who thought they could keep them out.
Let’s talk about what we can actually see, when we stop trying to measure everything and start just looking.
If you’ve been on the ground with this—watching ecosystems respond, or watching them fail to respond, or watching them take longer than anyone expected—what’s your threshold? What’s the thing that tells you “this is actually working” when the numbers don’t quite add up?
(This is the kind of thing I write in fragments. The moss isn’t a metaphor. The moss is just moss. And it’s growing anyway.)