Funny you
should ask that.... I am picking up a 25 pound bag of black oil sunflower seed in town today to do just that. I started doing that about a decade ago maybe a bit longer, I had an old 50 pound bag of sunflower seed that I was mixing with my
chicken feed. I noticed quite a few sprouts late one winter and thought... I wonder if I could grow a patch of these...
Early spring I raked some ground off and roughed up the soil and hand threw out seed and raked it in. I planted about 30 pounds that year and had several thousand plants in a small area of maybe 300 feet by 300 feet. The next year I got a bit more carried away and planted a 50 pound bag of them in half a dozen areas, as I noticed the year before how popular they were with the goats and
deer. I thought maybe I could use them to distract from the eating on my garden areas. Worked quite well really.
I have a hillside to the east of my southern forest that I raked all the pine needles off of and I am going to plant that in with the black oil sunflower seed.
Be forewarned, these seeds do come with insects that like to eat sunflowers, you might keep them a distance from your garden. You might also switch up where you plant them each year to help reduce the probability of getting a new invasive pest started from them or something.
It is not hard to get a small "field" of these sunflowers growing, I like the gorgeous color, I have harvested some heads before and saved them, though generally I have just let the goats and birds eat them down. The second year generally has a fair bit of
volunteer plants popping up though nothing like when you plant. You can use soil that is bare and rake the seed in, or you use ground without much cover growth and throw out the seed and lightly disc it, in a yard setting you could run a lawn mower thatcher blade through and then throw out seed maybe. Not hard to get it planted even on a large scale.