According to Texas A&M University, poppy seeds are sown in late fall. Seeds are scattered over bare soil and lightly raked in. Mixing the seeds with sand before sowing helps distribute the tiny seed more evenly.
It is illegal to grow Papaver somniferum, or opium poppy, in the U.S. Commonly grown varieties include the double flowered P. rhoes, or Shirley poppy; P. orientale, or Oriental poppy; P. nudicaule, or Iceland poppy; p. eschschlotzia, or California poppy; and P. commutatum, or Caucasus poppy. Annual poppies self-sow the next year if allowed to go to seed. Poppy seed is widely used in cooking.