Hi,
it should work similar to hunting, but instead of footprints you follow a scent to the flower/plant. The distance you would need to walk should force people outside of their town claim (10 tiles minimum, 40 tiles maximum distance) Should look like it's done in Witcher 3 imo: https://www.youtube.com/watch?v=Ynqxpx6TBQ0
Some important aspects:
1)
You should receive more than 1 item. 3 items per plant would be okay imo but I would leave that open for discussion. Your gain of items per minute should roughly be equal like the gain from auto-farming before the patch. Maybe you could get a random amount between 1 and 5 or so. Would be a nice way to make the luck stat more important.
2)
The quality of the ground should not deteriorate.
3)
Failed attempts should give skill points.
4)
The quality of the items you gather should be equal to the quality of the ground where the plant has spawned (limited by skill level of course, as it was before).