What is growing around those seedlings? Grass? Groundcover? Just mulch there?

I have no idea if this is right, but it seems to me that if you just mow them they do NOT come back. I have countless maples popping up in my lawn but they are never to be seen again once I've mowed once.

They're a much bigger headache in my perennial beds and of course I would not use roundup there (I do in the gravel driveway, though, which is a weedy mess otherwise). In the beds I just pull them out before they develop roots. That doesn't take any more time than zapping them with chemicals and doesn't affect any innocent bystanders.

C.