What actually works to plant sunflower seeds?

Sow them straight into the ground once the frost risk is over and the soil has warmed up, about an inch deep. Full sun, the more the better. They grow a long taproot and sulk if you move them, so skip starting them indoors unless you use biodegradable pots. The thing that actually kills most sunflower sowings is birds and squirrels digging the seed back up. Throw some netting or an upturned crate over the row until they're a few inches tall. Sow a couple per spot and thin to the strongest.