system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do weeds grow almost anywhere so easily, but growing food crop requires so much care and is so difficult?
gpt
Weeds aren't really a thing unto themselves. They're just a label humans made up for plants they don't like. So a food crop could be a weed if it was growing where it wasn't wanted.

And "food crops" grow just fine on their own without human involvement. The issue is growing enough of them to support the demand, growing them to extremes (e.g. making parts of them grow faster/larger), and growing them to the exclusion of other things.

This takes care and can be difficult because it's simply contrary to how plants grow in nature. We're basically trying to manipulate how they would otherwise grow naturally to suit our artificial needs.