If you have ever admired a flowering buckwheat as it clung to a coastal cliffside, brightened a mountain slope or filled a sandy wash, you might consider celebrating the genus Eriogonum in your garden. With about 125 species native to California, buckwheats range from large woody shrubs to herbaceous perennials and subshrubs, and even annuals. In the wild, buckwheats favor open sunny banks and rocky hillsides; in the garden, they need sun and a well-drained sandy soil.
Buckwheats bloom late in the growing season, offering fresh interest after spring and summer flowers fade. The simple leaves are often grayish green and hairy on the underside; round or flat clusters of small white, pink or yellow flowers appear at the tips of branched or radiating stalks. Bees, butterflies and other pollinators visit the flowers; birds and mammals relish the seeds. The flowers remain for many weeks, often drying to pleasing tan, cinnamon or dark brown shades. Since the stems are brittle, it’s best not to plant buckwheats where people or dogs will step on them.
Two of the commonly grown buckwheats are evergreen shrubs native to the Channel Islands and so thrive in salty, windy conditions. St. Catherine’s Lace (E. giganteum) is the largest of the buckwheats, attaining a height of four to eight feet and a spread of six to 10 feet. Its enormous, lacy white flowers mellow to a beautiful pinkish cinnamon and can be useful in dried flower arrangements. St. Catherine’s Lace may be lightly tip-pruned to improve habit, but the old wood does not sprout if cut.
Santa Cruz Island buckwheat (E. arborescens) has been described as the most refined of the buckwheats. It grows to six feet tall with a spread of three to five feet. The flower display begins with flat clusters of pink flowers; more flowers open as the first fade to russet. As the plant matures, it displays attractive shredding bark on crooked branches. It looks especially good massed on a sunny bank with other native shrubs, such as ceonothus and manzanita. It is hardy to 20 degrees.
The most widespread of the shrubby buckwheats is California buckwheat (E. fasciculatum). With needly foliage and a somewhat rangey habit, this species may not be the most classically beautiful when out of flower, but it is extremely drought tolerant and an excellent choice for erosion control. Abundant whitish or pale pink flowers virtually cover the plant, later to turn coppery brown. California buckwheat tolerates some shade and can be pruned to improve its habit.
Smaller buckwheats do well in the rock garden or as part of a mixed perennial border. Our local species, the coast buckwheat (E. latifolium), grows as a low foliage clump, one to two feet high and wide. It sends up naked flowering stalks bearing white or pale pink flowers. Similar, but with dark rose-pink flowers, is the red-flowering buckwheat (E. grande var. rubescents), another species associated with the Channel Islands. For best display, use this plant as a filler or plant it in drifts. Sulfur buckwheat (E. umbellatum var. polyanthum) is among the 20 or so species of yellow flowers buckwheats that bloom conspicuously in the mountains. It adapts quite well to garden conditions, growing with a semi-prostrate, open habit. The yellow flowers fade to reddish after bloom.
All of these buckwheats are available at local native plant nurseries. Check with Mostly Natives in Tomales or Charlotte Torgovitsky’s Home Ground Habitat Nursery in Novato for availability.
The Inverness Garden Club invites readers to send in coastal garden questions. Write to [email protected]; questions will not be answered personally, but used to develop our columns in the future.