Related Clues:
- Go off regularly on time, always at the start
- Decay (which can be dry)
- Give away, as a story's ending
- Tomato problem
- Arborist's anathema
- Go green, perhaps?
- Become unsafe to eat
- Rust on surface -- will nothing stop it?
- Turn putrid
- Decay, like wood
- Give away its final twist, say
- Go off tripe
- Go green, maybe?
- Get mushy in the fridge, say
- Ruin ground by injecting phosphorous