Perennial. Hardy in zones 3-8.
May be started inside 6-8 weeks before last frost in peat pots. Do not cover seed and provide cool conditions of 13°C (55°F). Often preferable to direct sow in early spring or late autumn, since poppies dislike transplanting. Transplant after last frost to a full sun location, 12-24 inces apart, depending on variety. Prefers well-drained, rather poor soil. Water regularly, but do not fertilize or use manure. Deadhead after blooming to prevent self-seeding, if desired. Iceland poppies do not need to be divided. Divide Oriental poppies only after they lose vigor from overcrowding. Move them in late summer after flowering has finished and the leaves have turned yellow.
Sow seed indoors 6-8 weeks before last frost, in peat pots. Gently press seed onto surface of soil and germinate at 10-15°C (50-60°F). Seed should germinate in 10-20 days. Move plants outdoors to a sunny location after frost has passed in spring. Plants will self-seed unless deadheaded. Poppies form a taproot and are not easily moved. If you must transplant, do so carefully in the fall or early spring, when the plant lies dormant.