I grow several thousand single-stemmed sunflowers each year, and I direct seed all of them. I am my only worker and seeding is so much faster than transplanting. I've toyed with the idea of starting some plugs to get an early jump on the season, but haven't actually done it yet. I've never used any support netting and have had only minor problems with wind.

ThinMan

any issue with uneven seeding due to variation in seeds' among varieties?

I plant just two varieties: ProCuts and Sunrich Orange. They both have fairly small seeds, and my Earthway seeder does a fairly good job of placing them, although there doesn't seem to be a plate that is exactly right.

As far as I know, the big boys all direct seed and I have found that even planting transplants at the same time as direct seeding, the seeded seedlings catch up to the tplants and they end up the same anyway. Kat

I seed mine (350 per week) in plug trays and then put them out, at about 3 wks old. If being grown in an area with heavy rainful and high winds I would think to use support netting. There's nothing worse than having to stand up sunflowers that have fallen over due to excessive sogginess of the ground.
Direct seeding would give you a stronger plant.
Cheers Kim - BFFF

Kim, why do you not direct seed? Do you have critter issues? Kat