I tried growing opium poppies a few times. I bought Afghan poppies and another kind, The only problum I had is I live in New York and the climate is not suitable for growing them ? But maybe I just messed up I don't know. The bottom line was I wasted my money. I Germinated the seeds I planted them they would grwo for awhile and then just die. I think in New York we get to much rain fall for them and the climate is not right. so I would say check out where you live and how opium poppies will grow in your climate. read up alot about them also, Good luck man.
In Australia all you have to do is scatter seeds, give them a bit of water and let em grow like weeds, you get wild plants growing everywhere.
Hate to tell you but its too late in the year, need to sew the seeds before the last frost. Thats how they know when to sprout in the spring. Also they need 3 months to grow till the days get longer to know when to flower.