I have a small tomato plant in a pot - a "late arrival" from among some generously donated to me by way of replacements for the ones which fared poorly enough during the "Spring deluge" of rain to croak on me.
All of a sudden these other things sprouted up out of the dirt in the pot for no readily apparent reason -
I've since identified them tentatively as sunflowers.
Thing is, I never planted them, and have no idea how the seeds got in there.
I thought they might have been squash at first, as I did try to start some sqash in small containers & tossed the dirt from 'em into a bigger tub to use for whatever when they didn't do well enough & I decided to just plant more right in the ground.
I guess unless some meandering squirrel stashed 'em in the pot, they must have been in a bag of dirt I bought or some damn thing.
The bonus is that I found out that sunflower sprouts are edible, so even though I think I'm going to try growing the ones in the pot to full size, I have another item to attempt to grow enough of to add to me old salad bowl !
Was there a whole batch of unshelled seeds in a clump? They would be the culprits then. If not, I'd put my money on our little feathered friends.
Squirrels is among our stooopidest peoples though. The silly things bust their humps securing food for the winter, then forget where they put it much of the time. It is funny to watch their antics when two or more belive the same stash is their's alone.
I'm certain if you got the ID of sunflowers from the seeds, but the tiny ones do look exactly like some kind of nusiance thing that regularly falls victim to roundup here at the fiefdom.