So a soft apocalypse is less of zombies etc, and more nature takes back. So in this case, what plants would be more likely to grow in and on buildings and in cities? Moss, Kudzu, etc?
Are you set in the south? Kudzu will take over a building without any need for the apocalypse, believe you me. Not sure how prevalent is is outside of my region. I did until recently have some moss growing on my shingles - only in the shade and quite slowly, though. I'd guess that's probably not your best bet. Other viney plants similar to kudzu, like types of ivy. It's pretty dependent on what's growing in the area before the world ends, I would think.
Yup. I'm a Georgia gal. Kudzu was the first thing that came to mind, but I couldn't think of much after that.
The older the buildings, the more plants normally in that environment that will take them over. So it depends on how far into the future you're setting it. But that's the idea. As the building crumbles and its frame wilts, soil builds up and the regular flora in the area sets in. Plants, such as trees, that make their way deep into a building will struggle earlier in the building's decay, but later periods will allow more growth as floors and walls break down from weathering. Some buildings will weather apart faster than others, even right next to each other, depending on their construction quality. Large skyscrapers will be some of the last structures to fall. Their foundations can be quite extensive, demanding many more years for soil to build up deep enough to support larger plants. But all of that also depends on soil health. You're not going to have many, if any, plants growing in the dirt if your apocalypse eliminates opportunities for organisms, such as worms and ants, to regularly mix the soil.
Look for the Life After People History channel series, it goes into everything that happens after the human race simply ends. ETA: Here's the trailer, although the show is narrated and not nearly as over the top. It also seems to be available on YouTube, but I don't know if that's legit or not, so I won't link here.
Great show. Amazing when you take real-world examples like Pripyat into account and see that indeed, without human maintenance and intervention, nature does her thing on a faster timeline than one might initially think.
Yep, was going to recommend that. I live next to the White Mountain National Forest in New Hampshire, and I can tell you that nature would take all this back faster than you can say "amber waves of grain."