The bread seed poppy, or opium poppy, forms attractive flowers in summer. If you scatter seeds of this wild flower plant in fall, they will start growing in spring, and form flowers by midsummer.
When to Plant Seeds
Papaver somniferum seeds need to be exposed to cold temperatures for about three months in order to bloom, according to Iowa State University. If you broadcast seeds in your yard where you want them to grow in fall, winter temperatures in many climate zones will be cold enough to do the job. If you live in a warmer area, such as USDA climate zone 9 or 10, keep your seeds in a plastic zipper bag in your freezer all winter. If you choose to plant seeds in the spring, you should also expose them to cold during the winter months.
How to Plant Seeds and Grow Poppies
Clear the weeds from your planting area, and dig in 1 part compost to every 4 parts of soil. Scatter seeds, and then barely cover them with soil. Keep the area damp until young plants are 2 inches tall. At that time, thin the plants to stand about 12 inches apart. Fertilise your young plants with a balanced fertiliser when they are about 6 inches tall. Keep the soil moist but not soggy until the petals drop from your flowers. If you are growing them for seeds, stop watering them when the petals begin to drop.
Expect Flowers in Three Months
The length of time can vary in different climate zones, but if you expose the seeds to cold for three months, plant them in spring, and keep them well watered, they should take about three months to bloom after the seeds are planted.