When my Oriental Poppy goes dormant, can I cut it back?
When My Oriental Poppy Goes Dormant
Certified GKH Gardening Expert
It may be best to leave them, with exception to the blooms. You can cut back the flower stems to the ground, but I would leaves the foliage alone as the plant will again wake up in fall and begin to put out new shoots. You can then cut back any old, dead growth. Here is more information on caring for these plants: https://www.gardeningknowhow.com/ornamental/flowers/poppy/growing-oriental-poppies.htm