I used to have big sun flowers in the front of my house and the yellow birds love them. I dunno what haoppen but one year, nothing came back anymore so I did not bother planting again. This year, I got one which I did not plant. I guess a burd drop a seed in my garden and it grew. It's not the typical sunflower that I used to grow (mammoth kind) but I was glad I got one as it might be a start again for many more next year.
I thought it will only have one flower but I was surprise that there are multiple small flowers that grew agter the big one.
I will save some seeds if the buirds t does not eat them all.