Iceland poppies are native to the northern parts of North America and Asia. Wild varieties have orange or yellow flowers on stems that tend to bend over. Well-bred varieties have strong stems with flowers that come in white, orange, yellow, shades of pink and blends of colors. They have petals that are thin enough that much sunlight gets through making them seem brighter than the usual flower. Sometimes catalogs list them as perennials however given that they don't handle heat very well they're often listed as annuals or biennials. Someone in Edmondton, Alberta, Canada wrote me to say that his poppies last 2-4 years.
The directions I've seen for Iceland Poppies include starting them where they are to grow because "they are difficult to transplant". Unfortunately I've found that you will get few (if any) plants by planting the seeds where they are to grow so I had to do it this way:
Get a pot you can water from the bottom, fill it with dirt, pack it down, sprinkle the poppy seeds on top, sprinkle enough powdery dry soil on top to cover the seeds and keep moist, preferably from the bottom although you can also mist from the top. Iceland poppies sprout in about a week. In hot weather the sprouts may keel over just after coming up so it is best to do this when it is relatively cool, indeed one set of directions said they need about 55F at night. I started with seeds from Park's but now I simply keep seeds from year to year. Because I have a lot of seeds the sprouts are very densely packed in the pot. When they are large enough and the weather is OK (relatively cool and damp) I simply dig out little clumps of the plants, set them in the ground and they do just fine.
They are also easy to start with Park's start cylinders, put a seed on top or inside and they sprout in about a week or two. Stick the cylinders in the ground when you have enough in the way of roots.
Iceland poppies are often listed as perennials but here in zone 5 it is unlikely that they will survive more than one year. Normally I start them in spring or summer for planting in the fall and then they bloom in the spring and summer although some might bloom right away in the fall. It seems its the heat that does them in so hot spots should be avoided. Keeping the ground cool with mulch may help keep them going. Iceland poppies like poor graveley soil however we don't have that kind of soil around here and I've never gone to the trouble of making some up. This may be a factor in why I lose mine so quickly.
The natural colors of Iceland poppies are red and yellow and if you keep seeds from year to year you will lose the pink, white, light orange and light yellow colors so save seeds only from these recessive colors. Mark the seed heads you want to save seeds from by putting a twist tie around the stem. Sometimes I use a tiny paintbrush to hand pollinate specific colors. Harvest seeds when openings develop at the top of the seed pod. Seeds only seem to be viable for a little over a year.