I moved to my land Jan. 2010. That first spring I planted sunflower seeds all over my septic system for the birds. None grew so I did the same thing in 2011. Then that fall goats showed up and in 2012 they enjoyed the sunflowers that started growing abundantly. I occasionally saw birds helping themselves too.
Well, it is now 2013 and not only are their sunflowers growing all over my septic system, but they are also growing in the fenced garden and there is one lone sunflower plant, which looks exactly like my sunflowers, growing along the dirt road approximately 2/3rds mile from my house.
As far as I have seen, no one else is growing sunflower plants around me. This is mostly hunting land, goat ranches, and retirement folks enjoying the countryside. Every time I drive by that lone sunflower plant I wonder what path the seed took to wind up so far from my septic system.