Romneya coulteri is native to Southern California and Baja California and Mexico. It is named after an Irish botanist Thomas Coulter. It is also called Canyon Poppy, Coulter’s Matilija Poppy, Californian Poppy, Bush Poppy, Giant White Californian Poppy, Dream of the Desert, California Tree Poppy, or Matilija Poppy. It is a member of the Papaveraceae family of plants. A suckering herbaceous perennial that grows in dry canyons and landscapes recently burned. It can grow to 2m or 7ft. It grows from rhizomes and produces divided grey-green leaves.
Giant White Californian Poppy flowers that are pure white appear in the summer. The flowers are large and impressive they grow to about 20cm or 8in wide. Romneya coulteri like the sun, plant it in moist but well-drained soil. They don’t like to be transplanted and they do spread naturally. Propagate by basal cuttings, root cuttings or by seed. Romneya coulteri is drought resistant. Watch out for Caterpillars and powdery mildew.