Poppies are easy to grow from seed but resent being transplanted, so sow them either directly in the garden or in peat pots. Sow seeds in mid to late March in the open garden. Do not cover the seeds because they need light to germinate. Choose a day when there is a light rain or snow. The natural precipitation will help the tiny poppy seeds make better contact with the soil and aid in germination. Keep the soil moist. In some areas, hens and chicks poppies will self-seed.
Poppies grow best in full sun in cool climates. Gardeners in warmer climates should plant poppies in an area that receives morning sun and filtered afternoon shade. Make sure the soil is well-drained and rich in organic matter. Poppies will not thrive in waterlogged soil. Transplant poppies started indoors under light into the garden on an overcast day after the danger of frost is past. Plant the peat pot, making sure the entire pot including the edge is underground so moisture is not wicked away from the plant through natural evaporation.
Poppies do not need excessive water or require fertilization. Water poppies during times of excessive drought or high heat, however. Organic fertilizers, such as fish emulsion or compost tea, slow-release fertilizers or a quick-release water-soluble fertilizer used according to the package directions is OK but really not necessary.
Once the poppy flowers fade, you will notice a round seed pod on top of the stem. This is where the seeds will form. Do not pick the seed pod while it is still green, unless you are using it in floral arrangements or crafts. In order for the poppy seeds to be viable, or able to germinate, the seed pod must turn brown. Collect the seed pods on a warm day, after a dry spell of two or three days. Crush the seed pods over a paper towel or plate, allow the seeds to dry and plant them again the following year.