Poppies Galore
If you travel round Europe, variations in colour can be found of this where natural selections have allowed for different shades to evolve.
Poppies prefer a cooler environment in which to germinate and grow, so spring and autumn are the best times to be sowing them.
All poppies have very small seed and prefer light to germinate so only lightly cover seed if you do at all.
Tamp the soil or seed raising mix down first giving a firm surface to sow onto.
Mist soil to keep it damp rather than heavily sprinkling it as the water droplets can wash the seed deeper and result in a variable germination rate.
Poppies do prefer to be sown directly in the garden but will handle transplanting if done carefully when small.
Plan on sowing some seed every few weeks to give yourself an extended flowering period when they mature.