Interesting point about mixing sedums with wildflowers—I've seen that done a couple of times, and it does create a nice aesthetic. I do wonder though, have you noticed any issues with root depth or maintenance when using grasses or wildflowers on roofs? I'm thinking specifically about how native grasses sometimes have deeper roots, which could potentially affect waterproof membranes or roof integrity over time. Curious if anyone's dealt with this or has insights on suitable shallow-rooted species that balance aesthetics, ease of maintenance, and structural safety. I've mostly stuck to sedums myself due to their shallow root systems, but I'd love to hear more about mixed plantings from those who've tried it firsthand.
I've experimented a bit with mixing sedums and wildflowers, and honestly, the aesthetics were great, but maintenance was trickier than I expected. Had a patch of native grasses that looked fantastic at first, but their roots went deeper than anticipated and complicated things when we had to inspect the membrane later on. Ended up switching to shallow-rooted species like creeping thyme and alpine strawberries—still colorful and attractive, but way easier on the roof structure. Has anyone tried herbs or edible plants up there? Seems like a practical bonus...
"Ended up switching to shallow-rooted species like creeping thyme and alpine strawberries—still colorful and attractive, but way easier on the roof structure."
Creeping thyme is a great call—I tried it myself on a small test patch a couple years back, and it was surprisingly hardy through winter. Plus, the fragrance when you step out onto the roof is a nice bonus. I did experiment with herbs too—mostly oregano, mint, and chives—and they worked out pretty well. Mint was a bit aggressive though; it spread faster than I expected and started crowding out other plants, so I'd suggest keeping it contained or in pots if you go that route.
One thing I noticed about edible plants is that birds and squirrels seem to love them just as much as we do... Had to put up some netting after losing most of my strawberries overnight. Still, it's satisfying being able to clip fresh herbs for cooking without heading down to the garden. Just keep an eye on weight distribution if you're using larger pots or containers—especially if your roof isn't reinforced for heavier loads.
