Strange sturdy/thick weed growing through/from woodchips?

Michigan, Zone 6a.
Any idea what this plant might be? I put 2-3 inches of woodchips as mulch on a pot that has been bare soil for a few years, and this started coming up. It seems to be growing in a cluster more towards the center, but it is also spread throughout the pot.
I've never seen this seedling anywhere else, so I'm assuming it is something that came with the woodchips or something that was buried in the soil and required wetter conditions to germinate.
It comes out easily but has a noticeably thicker stem than I've seen on other seedlings.

To me it looks a bit like some type of pumpkin or squash, although I highly doubt it would be that. I'm tempted to let one grow and see what it is, but I thought I would check and see if anyone knows before I lose the opportunity to grow something else in this pot.

What a fun mystery! Those look very much like the sunflower microgreens I grow, which also have super sturdy stems. Any chance this pot was near a bird feeder at some point?

Logan Byrd wrote:Michigan, Zone 6a.
Any idea what this plant might be? I put 2-3 inches of woodchips as mulch on a pot that has been bare soil for a few years, and this started coming up. It seems to be growing in a cluster more towards the center, but it is also spread throughout the pot.
I've never seen this seedling anywhere else, so I'm assuming it is something that came with the woodchips or something that was buried in the soil and required wetter conditions to germinate.
It comes out easily but has a noticeably thicker stem than I've seen on other seedlings.

To me it looks a bit like some type of pumpkin or squash, although I highly doubt it would be that. I'm tempted to let one grow and see what it is, but I thought I would check and see if anyone knows before I lose the opportunity to grow something else in this pot.

It's a little hard to get a sense of scale. They're roughly the size of squash seedlings? So 1-2 inches?

Lew Johnson wrote:It's a little hard to get a sense of scale. They're roughly the size of squash seedlings? So 1-2 inches?

Yes - they're around that width as far as leaf span goes.

Jennifer Kowalski wrote:What a fun mystery! Those look very much like the sunflower microgreens I grow, which also have super sturdy stems. Any chance this pot was near a bird feeder at some point?

I think you might be right! There has not been a bird feeder close to the pot, but I did set up a bird feeder this year and I've seen birds digging through these pots, so I would not be surprised if they put sunflower seeds there for some reason.

lol - i would say sunflowers too - i feed birds year round - i see those here there an everywhere in the spring

This has been fun to observe! I set up a camera to record that pot, and I've seen birds fly down to drop off seeds, and I've also seen birds eating the sunflower seedlings.

Clearly they're better at gardening than I am!