Hi keith, I think because they are annuals you would need a light like daisy said! I don't think it would be easy setting up lights for sunflowers! You can however grow them indoors from early spring, for a while anyway! I have seen pots put on their side and the sunflowers growing sideways along the windowsill until it heats up outside, i would assume the main stem would be very tender growing this way.
Llike sally said they will grow very fast in full sun and warm soil! Even if your seedlings make it through the winter, the ones planted in spring will quickly catch up come summer! I think the most you would get out of it would be early flowers!
