Wow those are some tall sunflowers! Never had mine get that big!!!!

I've never staked my sunflowers but I have had them fall over, snap and break (they were quite large at that point). Maybe this year as they get bigger, I'll put some sticks to help support them, at least at the base, until they are strong enough.

Two years ago my DD took sunflowers from her hamster's food and planted them. Boy did we have beautiful sunflowers that year!! We had some interesting corn too!