One of the great advantages of knowing a bit about the different garden plants is that I can take one look at a seedling and then decide if it is a weed or a self-seeding plant from last year.
Then I can carefully dig up some of the seedlings and gather them on spots they can grow big on. The rest goes in the compost bin together with common weeds.
Castor bean is another really eager self-seeder. I have written about them before here. It’s almost shamefully easy and convenient and has som avid self-seeders in the garden here in Texas.