We have a mystery sunflower that has grown this summer in our garden. Don't know where it came from but it initially got to about 8 plus feet tall and then one morning had bent over to the ground. I'll attach a photo of it so you can see what that looks like. I was going to cut it off but my wife told me to leave it and see how it turns out. It has been a spectacular sunflower and I'm wondering if anyone knows what type of sunflower this is and if the bending over is normal once it gets heavy enough.

It may be Black Eyed Susan - Rudbeckia hirta. A native wildflower that seems to come up everywhere, at least around here.

Could be Swamp Sunflower (Helianthus angustifolius)
? Maybe?

Possibly some sort of native sunflower, Helianthus annuus. Birds, squirrels, mice etc. will sometimes drop or bury seeds, or it might have just blown in. They grow along the roadsides here.
I think it looks great, even fallen over. I suggest you let it go to seed. Birds love the seeds, and it will self-sow for more next year.
That's a nice looking flower bed!

It's likely Helianthus anuus, common sunflower. Although normally upright, wind, rain and damp soil can cause then to bend and/or tip over. They tend to be stockier in barren, dry soil but really shoot up in moist or cultivated conditions. Yours has come up in your cultivated bed (beautiful, btw) and is so exceptionally floriferous that the weight of all the flowers were too much for the stalk.

If you let them go to seed, they'll return every year. Easy to pluck out as seedlings if you don't want them. The seeds are favored by goldfinches... they'll return every year, too!

NMoasis said: It's likely Helianthus anuus, common sunflower. Although normally upright, wind, rain and damp soil can cause then to bend and/or tip over. They tend to be stockier in barren, dry soil but really shoot up in moist or cultivated conditions. Yours has come up in your cultivated bed (beautiful, btw) and is so exceptionally floriferous that the weight of all the flowers were too much for the stalk.

If you let them go to seed, they'll return every year. Easy to pluck out as seedlings if you don't want them. The seeds are favored by goldfinches... they'll return every year, too!

The problem with that theory is that it was probably 9 feet tall with no blooms when it tipped over - they were just starting to form. Thanks for the reply.

Maybe wind, maybe it just felt lazy. Regardless, the answer to your original question is: I'm reasonably certain it's H. annuum, and yes they sometimes bend.