Good sunflower seeds for birds should be fresh, and therefore should sprout pretty well. I have planted rows of them to break up clay soil and they did the
job and some grew up to 10ft tall with dinner plate sized flowers. Others were 2ft, but I hardly watered after the first 2 weeks and really gave them very little care.
People stopped in middle of the road to tell me how much they liked them. I am going to get a 50lb bag and sprout them to grow and for my fowl.