Guerilla gardening is baby steps anarchism. It's breaking the law and fucking the police in such an inoffensive way that no reasonable person could say you're a bad person for doing it.
And if it turns out to be your thing, you can graduate to dumpster diving and tactical urbanism and feeding the homeless without a permit.
Gardening, guerrilla or not, is local production, one translation of swadeshi, the core of Gandhian or nonviolent economics, a daily practice
Gardening can be extremely powerful:
USAmerican WWII Victory Gardens began in Spring 1942 & by Autumn harvest 1944 were producing a third to a half of fruits & vegetables on the Home Front
Now,
imagine Climate Gardens using known regenerative techniques of carbon drawdown
&
what could be done in more than only two growing seasons