With its big, showy spring blooms, Oriental poppy (Papaver orientale) is impossible to miss. As long as Oriental poppies are planted in well-drained soil and full sunshine, they require little care, but can be rejuvenated by transplanting the poppies every four to five years. However, keep in mind that because of its long taproot, transplanting the Oriental poppy can be a challenge. The best time to transplant Oriental poppies is in late summer, when the poppy plant isn't actively growing.
Prepare the ground for the transplanted Oriental poppies ahead of time so the roots won't be exposed to the air any longer than necessary. Use a shovel or a rototiller to cultivate the soil to a depth of 12 to 14 inches, then mix in 2 to 4 inches of compost.
Dig a large circle around the perimeter of the Oriental poppy plant with a sharp shovel. Dig deeply, then lift the clump of Oriental poppies out of the ground. Work carefully and try to keep the roots intact as much as possible.
Dig a hole for the Oriental poppy in the prepared spot. The hole should be the depth of the poppy's root system, but at least twice as wide. Put the poppy plant in the hole with the top of the roots even with the top of the soil, then fill in around the plant with reserved soil. Tamp the soil down with the back of the shovel.
Keep the soil moist for the first four to five weeks while the roots are getting established. After that time, Oriental poppies need water only during periods of hot, dry weather.