I am interested in planting black oil sunflowers to show at the county fair next year. I am really interested in as large of head as possible, although I know they will not get as large as the grey striped sunflower. I will probably plant both and enter one entry in my name and the other in my wifes name. They compete against each other and it is 2 heads and are normally judged on uniformity, size and fullness of seeds. Where to get black oil sunflower seeds. I am considering just planting seeds from bird seed but was wondering if they were a hybrid, the seeds I plant may not breed true. Also, any hints for growing large heads. I understand close planting and lots of nitrogen gets tall plants. I am considering 3 foot spacing for grey striped and 2 foot spacing for the black oil ones.
Thanks
Bucky