Shirley poppies are an annual version of the older perennial varieties of poppies. They are low-maintenance and easy to grow. These paper-like flowers are one of the few annual flowers that grow best when their seeds are planted the previous fall. Shirley poppies bloom in mid to late spring, depending on your location.
Pick a site to grow the Shirley poppy that is in full sun with light, well-drained soil. The soil should not be very fertile; Shirley poppies prefer unimproved soil.
Prepare the planting site. Spread a 2- to 4-inch layer of sand on the surface of the soil. Turn it over with a shovel or rototiller to loosen and incorporate the sand. Rake the area smooth.
Sow seeds in late fall. Mix the seeds with a handful of fine sand to ensure they are more evenly spread. Broadcast the seeds into the seedbed. Do not cover with soil, but lightly press the seed into the seedbed with your hands. Do not water or cover with mulch.
Thin seedlings after they emerge in spring when they are about 2 inches high so they stand 8 to 12 inches apart.
Mulch the soil with 2 inches of shredded leaves or buckwheat hulls.
Provide Shirley poppies with the equivalent of 1 inch of rainfall per week.