Heavy shade is definitely a challenge for green roofs, especially under big trees like maples. Sedum usually needs at least a few hours of direct sun, so under dense canopy it’ll struggle—patchiness is pretty common in those spots. I’ve seen moss take over in wetter climates, which isn’t always bad, but it can mean drainage isn’t ideal. Sometimes swapping in shade-tolerant natives or even letting moss do its thing works better than fighting it. Constant replanting gets old fast... but you’re not alone in running into this.
Sometimes swapping in shade-tolerant natives or even letting moss do its thing works better than fighting it.
I get the appeal of just letting moss take over, but doesn’t that mess with the drainage long-term? I tried ignoring a moss patch last year and ended up with standing water after heavy rain. Anyone actually had luck with shade-tolerant natives holding up without constant maintenance? I’m all for low-cost solutions, but not if it means more repairs down the line.
I hear you on the moss. I let a patch go wild behind my garage, thinking it’d be less hassle, but after a couple storms, it turned into a mini swamp. Ended up having to dig out a bunch of soggy soil. I’ve had better luck with ferns and wild ginger—still need to trim them back sometimes, but at least the water drains. Moss just seems to hold onto every drop.
Interesting, I’ve actually had almost the opposite experience with moss. Maybe it’s the slope or the soil type, but in my backyard (clay-heavy, decent drainage), the moss patch seems to soak up water after a rain and then dries out pretty fast. I wonder if it’s more about compaction or shade? Did you notice if your “mini swamp” area was getting less sun or had more foot traffic? I’m still trying to figure out if moss is a friend or foe for runoff—sometimes it feels like it helps, other times it just makes mud.
That’s interesting—my mossy spots actually seem to hold onto moisture for days, especially in the shadier corners. I wonder if it’s less about compaction and more about how thick the moss layer is?
I get that. For me, once the moss gets established, it almost acts like a sponge, but if there’s bare soil mixed in, it turns into a mess after heavy rain. Maybe the difference is how much organic matter is underneath?“sometimes it feels like it helps, other times it just makes mud.”