Sanguinaria canadensis aka Bloodroot

Sanguinaria canadensis, or bloodroot, belongs to the poppy family. It grows wild in central and eastern Canada and the United States. This perennial grows from thick rhizomes, which are underground stems. It lives in rich woods, thickets, and near streams. Its red-orange sap gives bloodroot its name. Cut rhizomes release this sap, which people once used for dye. They also used it as an insect repellent.

Plants usually stand about 0.5–0.8 feet [0.15–0.25 metres] tall. Missouri Botanical Garden lists a spread near 0.5 feet [0.15 metres]. RHS gives broader height and spread ranges, reaching 1.6 feet [0.5 metres]. Rhizomes spread over time and can form large patches. Each flower stalk rises wrapped in one folded leaf. The leaf opens as the flower blooms. Leaves look green to blue-grey and have five to nine lobes. Their edges have blunt teeth or rounded scallops. Leaves last until midsummer, then die back as plants go dormant.

Bloodroot flowers in early spring, often from March to April. Chicago Botanic Garden also notes flowers in April or May. Each stalk bears one white flower with a yellow centre. Some petals have a pink tint on their backs. Flowers measure about 1.5–2 inches across and have several petals. Two sepals drop away when each bloom opens. Flowers open in sunlight and close at night. Each bloom lasts just one or two days. Bees visit the flowers. Green seed pods hold brown seeds that ripen in April or May. Ants help carry the seeds away.

Grow bloodroot in rich soil that stays moist but drains well. Part shade to full shade suits woodland plantings. RHS also permits sun in suitable growing conditions. The plant accepts acid, neutral, or alkaline soil. It tolerates dry soil and drought, despite its preference for moisture. Sources list USDA zones 3–8 and RHS hardiness H5. Plant it in groups in woodland, native, or rock gardens. It gives seasonal ground cover beneath taller plants. It needs no pruning and has few serious pest or disease problems.

Divide plants in spring or autumn, or sow seed in autumn. Seed may sprout unevenly over the next two years. Bloodroot has a history of medicinal use, but it is poisonous. The roots can cause vomiting, diarrhoea, dizziness, fainting, and heart failure. It also poses a risk to pets. Its sanguinarine content adds a further safety concern. Do not treat its past medicinal use as proof of safety.