A perennial sub-shrub which can be grown in the well-drained border and on the rockery. A compost of sandy loam, with an addition of leaf-mould and peat is excellent for cultivation.
Plant in late spring, in a well-drained, sunny spot. During the winter they will need a protection of litter or bracken. Take root cuttings during February, insert singly in small pots and stand in a temperature of 55 degrees. Seeds may also be sown in spring in the same temperature as given for cuttings.
R. Coulleri (Tree Poppy), reaches a height of 4-8 feet, and bears white flowers with golden yellow stamens. This plant flowers during August.