I love the idea of the massive spikes and thorns. They seem to me a relatively naturalistic type of warning. To me it seems unlikely that very spiky spikes stop to mean "flesh-piercing" at some point and take on a homely "let's settle here, in the shade of these enormous spikes, let's till the ground and dig wells" kind of atmosphere.

Here are some artists impressions of how that might look:

https://daily.jstor.org/wp-content/uploads/2015/05/NuclearWa...

https://ratical.org/radiation/IntoEternity/spikes02.jpg

https://i2.wp.com/media.boingboing.net/wp-content/uploads/20...

(Edit: better formatting)