When I visited the California Academy of Sciences a few years ago, right after they opened, I was enchanted with their green roof, which was, at the time, very new. Last week, I went back and found that the roof had matured and looked even better.
It was interesting how the coconut fiber baskets that hold the earth and plants in place are now completely invisible. I had visited Rana Creek Nursery a short time after I'd seen the green roof for the first time and was quite enchanted.
Now, you wouldn't know there are baskets under the lush green (and some brown earth) though the drainage rocks still show this roof is planted and maintained by humans.
It's possible to walk all the way up to the roof and enjoy the view of the roof. Educational signs and occasional presentations make the roof beautiful, a great help with energy conservation and supporting the insects in Golden Gate Park, and a teaching tool.
I found it interesting to see an area of new planting, and appreciated the choice - some native buckwheats and grasses. The sign said that over 70 different plant species have been planted on the roof, most of them native plants!
And even in October, the golden poppies and monkey flowers made for a pretty picture (though the hummingbird sage was a little past its prime).
Don't miss the Academy if you're in the city. It's no longer as crowded as it initially was, especially on a weekday, and there's so much to discover. And besides, this is another way to support the organizations that support our native plants!