Oriental poppies relish the cool temperatures of early spring and fall. Field poppies and opium tolerate drier, poorer soils than oriental poppies, while Himalayan poppies do best in moist, slightly acidic soils, in partial shade. Celandine Poppy is a woodland plant with yellow and orange flowers rising to 3 feet tall and 3 feet wide. The flowers bloom on top of the leafy foliage, near the top-end of the stems. They can leave quite a big gap in a herbaceous border though Some of the common names for Romneya include Matilija poppy and California Tree poppy. Books for Gardening. Pruning Gear: Lightweight pruning scissors for regular, selective pruning; Bypass pruners for minimal deadheading (cutting-back) To resolve this issue, selection of the right pruning gear is critical. After blooming heavily for 4-6-8 weeks, the plants become leggy, some of the older foliage may become unsightly or spotted, and there are many dead seed pods mixed in with the new buds and flowers. Romneya species are half hardy perennials that range from 90 cm to 1.8 m in height. Most poppies come true if propagated by seed but oriental poppies should be propagated from root cuttings. There are different pruning strategies for different times of the year, but overall the goals are the same - to keep the plants looking fresh and open, promote new growth and re-flowering, and to improve the overall health of the plant. Thus, precisely pruning the columbine flowers becomes a demanding task. • Matilija poppy (Romneya coulteri): O’Brien says if growing vigorously after a year, prune hard, cutting back all the old stems to stubs only 3 to 4 inches from the ground. Such pruning enables the plants to direct their energy towards growing healthy shoots and blooms. Apply the mulch late in the fall, after the ground has already become cold, and if possible wait until the first frost. Here at my Bedford, New York farm, it's time to "prune after bloom" - meaning deadhead all the faded flowers in the gardens. For most species, deadhead spent blooms to prolong flowering. The California poppy is a study in contrasts. Cut all stems and foliage flush to the ground. How to care for oriental poppies includes allowing them to die back. If they are emerging from the base of the plant, you can remove the old stems by cutting them to ground level. For a short-lived bouquet, you can try harvesting mature buds before they first open. Oriental poppies also benefit from a vicious cut-back after flowering. Their bright blossoms open just as most spring bulbs are finished and before the summer flowers begin. California Poppies don’t make good cut flowers. Before pruning, check whether the new shoots develop from the base of the plant or from old stems. They have a woody nature, and bloom with flowers reminiscent of poppies in the summer and early autumn. The plants are vigorous, and often grow in vacant lots and roadsides with no tending. Shear back a plant after its initial heavy bloom period to encourage new growth and repeat blooms. Guide to Growing Matilija Poppy and Tree Poppy. During cool-to-warm weather after plants have completed bloom cycles, provide supplemental water and deadhead to encourage reblooming. Summary. So many novice gardeners have killed their oriental poppy plants through misdirected concern. If oriental poppies are cut back quite hard after flowering and watered if dry, they will grow a flush of new leaves and sometimes give a second flowering in September. Many perennials are long and repeat bloomers. They lose their petals quickly after flowers are cut. The flowers are not the only draw to gardeners; the leaves are very attractive as well.