Dear WeatherCat watchers of the seasons turning,
I spotted an even more extreme example of California poppies growing out of a seemingly impossible location:
These flowers are literally growing through the stone wall behind them and are looking perfectly healthy. In contrast here are some poppies dueling it out with wild grasses:
Given that poppies can't outgrow grass, they do best in places were grass cannot grow. So a stone wall will due if they can run a shoot beyond the rocks.
Cheers, Edouard