hi .. welcome to GW ... you got it last w/end.. and you have already fertilized it twice??? one might suggest you are on the verge of loving this thing to death ... and you water it when it needs water ... insert finger.. that medium looks rather peaty to need watering every other day ... but it is really up to your finger to figure that out .... and when i bring home a plant.. i NEVER place it out in full sun .. since i have no idea if it is acclimated for full sun .. i would give it a few days in very bright shade.. to get it hardened off... and then start moving it toward full sun ... [it looks like a greenhouse plant.. and any glass between the sun and a plant.. in theory.. is not full direct sun ..] .. and with the plant getting rather large.. and the pot getting smaller.. i might avoid full sun altogether ... the pot just might not be holding enough water for all day in the sun .... put it in bright shade .. water it properly.. dont fert it for at least a month.. and then very diluted.. and just enjoy it... once it goes to seed.. there wont be anymore flowers.. unless you take that one off .... good luck.. and good day ken ps: dont make presumptions just on the name.. because.. in this case.. a sunflower.. probably should be in mother earth.. rather than a pot ... and that is where problems start ...

Good morning! I probably planted 15-20. At least 10 sprouted over an area of 14'x 3ish'.

It's probably flowering early in response to the shortening day length. That's natures way of assuring seeds before freezing weather. In your zone nature was a bit early. But in other areas of the country the response would be spot on with planting that late.

FWIW, velvetleaf is a listed invasive or noxious weed in many areas. That's not to say the plant in question may be attractive to some or even of some beneficial or medicinal purpose......however being assigned the title of invasive or noxious weed indicates the plant poses an ecological threat to some measurable degree. It is of particular concern in agricultural areas, as it invades croplands and outcompetes food crops, typically corn and soybeans. It is an extremely difficult plant to control, as each plant produces upwards of 17,000 seeds and these remain viable for 50-60 years.