Is there any way to prevent unauthorized players from planting in flower pots?

What kind of flower pot?! I'm not aware there is any flower pot in the game.

planter.large

The whole plugin is about block plant, from anybody who is not the owner of the small and big planterbox. So yes, it is preventing it.

You didn't understand what I meant. What I mean is that if the player is not the owner of the planter. target, other players cannot plant any plants on it, including stealing any plants.

This plugin prevent from planting, stealing, cutting anything, what is not doen by the owner of the planterbox. Try out and use it, or explain your need better. So far the plugin does everythign what you said.

The current issue is with unauthorized plans Target, other players can plant any plant inside. And it can also collect and harvest.