I've heard it bith ways, that you do leave the stalk after cutting it down and that you need to eliminate the stalk.

In other games, you have to cut down the stalk also, to keep it from respawning.

Is it the same here? 

Thanks. 

Yes, you must remove the stalk to keep it from growing again. Note you cannot build anything if the stalk is in the way. 

My experience with the game is that it doesn't matter if you remove the stalk or not. After a few days pass and then sleeping, everything will grow back except weeds.

1 hour ago, AcousticColors said:

My experience with the game is that it doesn't matter if you remove the stalk or not. After a few days pass and then sleeping, everything will grow back except weeds.

So if I remove a plant to place a foundation,  it'll grow back or will building where plants were chopped down keep them from respawning? 

There is currently no way to 'keep grass' and things from growing back - unless you build nearby it.  I am testing removing the 'stumps' and building a light in it's place right now, but I do know the foundations (the weed stem scaffold and the clay) both have prevented re-growth, as well as a small radius around them (maybe half the width of the foundation)

Hopefully, in the future, removing the stump will simply disable regrowth, allowing players to pick which ones to 'permanently remove' (maybe make some form of fertilizer to regrow, expensive cost for small radius.  This will also allow you to 'clear cut' an area to see better, or , to plan traps for wandering enemies.

Go get some clay and build Clay Foundations wherever you don't want them to spawn. I did this in my base and have not had a single thing grow inside my walls. I don't know if you can do the same with floors, but I can confirm that Clay Foundations do the trick.