Cultivation and Propagation: The California poppy is grown as an annual in cold winter area, and as a perennial in California and the South. The seeds should be sown where the plants are to stand, as they don't transplant well. They should be sown as early as weather permits. The plants like a sunny exposure and do well on hillsides and dry, rocky places. In the garden, the seedlings should be thinned so that the plants will stand 6 to 8 inches apart. They stand considerable cold and will continue to bloom after the first frosts. In cold areas, if the roots are protected, the plant will live over winter and bloom the following spring.
Harvesting: The outer leaves may be picked and dried at any time. The flowers may be removed and seed capsules may be picked when unripe and dried with the leaves. In autumn the plants should be cut off at the ground and dried before they begin to wilt from the cold.
These plants are quite cold tolerant and will survive even severe Winters if the roots are protected by mulch. Propagate by seed.
Leaves, flowers or seed pods should be harvested before the first major frost by cutting off at ground level. The plant material should then be slow dried out of the sun.