we cant plant seeds outside planter boxes anymore.

Rust updated, and now we can't do that any more. You need to update the plugin accordingly 

Changed Status from Pending to Work in Progress

I just checked on the latest versions of Rust and Oxide. I have no problem planting seeds outside of planter boxes.
Do you have any error in the console?

https://www.dropbox.com/s/p631b4qmju40urk/Timeline 1.mov?dl=0

Changed Status from Work in Progress to No Response

Maybe another plugin requires it? Is the server on a stable version or staging?
Have you tried testing the plugin alone, without other plugins present?

Can you show my your plugins list?

After some searching on google. It turned out "Must be planted in a planter." is called by the 'Tree Planter' plugin. Remove or disable it, otherwise 'Natur' will not cooperate.

Changed Status from No Response to Closed