This is a question that had been going through my mind this past season as I continue to learn about plants. There's a Biblical saying about letting the weeds grow among the wheat until they are both old enough to determine one from the other and sometimes this is what I think it comes down to for me. Thankfully, not many weeds seem to run rampant, despite the weed farm next door, and easy enough to pull the odd unwelcome guest.

What Jen said.

The seedling in the 1st pic with the leaf resting on the stone is a Rudbeckia.

i agree ... you let things go to flower ... THEN ID ... and then remove unwanted things asap ...

its how i had to learn.. back in the stone age.. when there was no WWW

ken

But you won't have to take that approach for ever. Soon you will be able to id weeds and wanted plants at the seedling stage.

The only weeds I pick as soon as I see them are crabgrass and pigweed. Others, like all the more knowledgeable folks have mentioned, I let grow until I can identify as friend or foe. I have a LOT of similar looking seedlings you pictured which for me could be either rudbeckia, Echinacea, or something else unknown. I guess the fun is letting things come up and seeing what they turn out to be!

"I guess the fun is letting things come up and seeing what they turn out to be!"

And then trying to figure out how that plant got its seeds all the way across the yard.

Same, to pretty much everything you said! Something I've learned is that there often are several in one spot. for instance I'm pretty sure in that second photo you've got a tiny little rudbeckia leaf at the bottom. If you're anything like me you'll murder a whole batch of plants thinking they're ragweed or plantain only to realize your mistake later when a plant that escaped your attention blooms. For me those seedlings are the easiest to ID. I also learned that while some seedlings true leaves look really similar early on, their seed leaves can be totally different, like tomatoes and ragweed.

They look like echinacea to me. I have them as well as 2 types of rudbeckia that reseed out of control. The birds or the wind sow them if I don't deadhead. I like to see the birds out there flitting among seed heads, so I end up weeding out or giving away volunteers.

I'll echo what a few others have said above--when you identify a "volunteer," don't be hasty yanking it out. I winter sowed columbine seeds 5+ years ago with nary a sprou to show for the effort but the nursery-grown columbine varieties I'd planted self-seeded (at will) and have given me a half dozen or more plants. They're elegant, with some purple ruffled with white and others different colors. They also come up in cracks between my driveway asphalt and garage foundation, again at will. I welcome them each and every one, wherever they appear.

You'll gradually become familiar with each plant's unique leaf shape (columbine leaves have a scalloped edge) and learn which not to yank. Even when I recognize briars and other invasives, I leave them until they've reached a size that makes it easier (for the ND neighbor's teen) to yank them out.

I want my beds to be a colorful hodge podge and am trying to encourage reseeding, spreading, and generally filling all available space.

That's what I set out to do back in 2006 and can admit I achieved my goal over the past decade.

Did you ever plant comfrey by chance?.....The bottom picture looks an awful lot like a comfrey seedling.

When in doubt don't pull it out. That's what I've learned to do. It's easy to yank it out later if you determine it's a weed, but once pulled you can't bring it back.