Bitterroot

Credit: Richard Hebda

Bitterroot grows from a gnarled reddish rootstock that has a somewhat woody crown. In the early spring and sometimes even in the fall, numerous cylindrical to club-shaped leaves, about 1.5 to 5 cm (1⁄2 to 2 in.) long, grow from this crown, then dry out by flowering time in May. Striking, 3- to 7.5-cm-wide (1.5- to 3-in.) flowers emerge as if by magic upon the soil, scarcely rising 2 to 3 cm tall (1 in.). A single flower occurs per stalk, but a handful of flowers may open on each plant, displaying beautiful clusters of white to deep-pink blooms. Pink forms usually have a contrasting white or warm-yellow centre. Each flower resembles a miniature water lily. Six to nine greenish sepals cup a ring of about 15 narrow, somewhat overlapping petals. At the centre there is a mass of 20 to 50 yellowish stamens surrounding 4 to 9 stigmas. Ovules mature into small capsules that produce moderate-sized seeds. In British Columbia bitterroot occurs widely in the Thompson and Okanagan region and in the southern Rocky Mountain Trench of southeast B.C. Southward the range includes inland portions of California as far east as Colorado. The species thrives in hot, dry, stony or sandy soils in grasslands and sagebrush habitats in British Columbia. Look for it on valley bottoms and adjacent lower slopes and terraces. Bitterroot was a vital source of food for First Nations of the southern dry B.C. interior and adjacent U.S. states. In spring, as the flower buds appeared, the fleshy roots were unearthed with digging sticks and their bitter outer covering peeled off. They could be cooked fresh or dried for long-term storage. When cooked, the roots swell into a gluey mass many times their original size. Bitterroot, salmon eggs and saskatoon berries were combined into a nutritious, pudding-like food. To the Okanagan peoples bitterroot was the “king” root and a special ceremony was held in the spring to celebrate the harvest. Bitteroot is a plant for dry, sun-baked rock gardens with very sharp drainage. It does not tolerate neighbours that shade or crowd it, thus reducing drying airflow. You can raise it from summer-collected seed, which is sown as soon as it is ripe in very sandy, even gravelly soil. Leave it to germinate over the winter and allow two years for it to become established. Expect flowers four to five years after sowing. Mature plants can be moved during the dry dormant season and will resprout the following spring. In dry inland climates, bitterroot grows easily in the open stony rock garden. On the coast I would suggest planting it on the south-facing lip of a rock garden in gravelly soil over rocks. Unfortunately, long wet winters or wet summer soils lead to collar rot and loss of the plant. You can grow it in a ceramic pot in gritty soil under glass so that it bakes in summer and misses out on winter rain. Under glass, withhold water from the end of bloom period until new, green growth appears in September, then apply light regular watering with new fall growth. Incidentally, the succulent genus Lewisia is well-known to gardeners through the widely available Lewisia cuisia cotyledon in its many attractive and interesting colours. It, by the way, is a native North American species from Oregon and California. Interior gardeners, Lewisia rediviva is for you. Coastal gardeners, with some site preparation and patience you may be able to have it too. The following plants are hardy to the zone number indicated: • Lewisia cotyledon – zone 6 • Lewisia rediviva – zone 4 An expert on native plants, Richard Hebda is curator of Botany and Earth History at the Royal British Columbia Museum in Victoria.