Gardeners and landscapers prize the Papaver somniferum poppy for its green foliage and delicate white blossoms. It's sometimes called the breadseed poppy because chefs can use it in baked goods, according to Washington State University. The plant's very fine seeds self-sow after blossom production and, given the right germination environment, will grow into new poppy plants.
Like most plants, poppy seeds grow best in slightly acidic soil, according to Poppies International. Slightly acidic soil has a pH ranging between 6.5 to 7.0, according to the Toronto Botanical Garden. Many garden stores sell soil testing kits that can pinpoint the soil's current pH levels. A pH that's too low can be raised with agricultural lime, while soil that's alkaline can be lowered with urea phosphate. The amount needed to adjust the pH appropriately varies depending on the soil amendment and the degree to which the pH needs to be adjusted. Your local cooperative extension office can offer further directives.
Breadseed poppy seeds germinate best in soil that's 59 degrees Fahrenheit, according to Purdue University. This makes them less cold sensitive than many other varieties of poppies, which prefer warmer dirt.
The seeds experience optimal germination and growth in well-drained, deeply tilled soil that's kept consistently moist. Though the poppy can tolerate sand and clay soils, a medium-heavy loam is best, according to Purdue University. Gardeners can amend soil as needed with fine, organic matter such as aged compost until the soil is crumbly in texture.
Poppy seeds must be spaced sufficiently to allow for adequate growth once they germinate. Purdue University recommends that the seeds are sown 4 inches apart. If rows of poppies are being grown, gardeners should space each row apart by a foot.