Coulter’s Matilija Poppy (Romneya coulteri) is one of the largest and showiest California poppies. Large white petals with a crinkled texture surround yellow stamens, giving this poppy a bright, cheerful appearance. Its flowers, which can be as large as 7 inches across, are attractive to bees and butterflies.
This plant can be challenging to establish, as it can suffer from both too much and too little water. Once established, however, it readily spreads by rhizomes and can soon outgrow its intended area. (Pulling shoots usually suffices to control it.) Plant in full sun in well-draining, sandy soil. Matilija Poppy is a low-water plant that does not need supplemental summer irrigation once established.