Wild Buckwheat in the Yard and on the Trail

Wild buckwheat is a shrub or mat-forming perennial in the genus Eriogonum, native to western North America, and it is not the plant that produces the buckwheat flour sold in stores. That flour comes from Fagopyrum esculentum, an annual in the knotweed family, grown as a grain crop in Asia, Europe and the northern United States. The two share a common name and nothing else: different family, different continent, different use. One is harvested and milled; the other is planted once and left in place for years.

The confusion costs gardeners time. A packet of buckwheat seed from the grocery aisle will sprout in a dry bed and die by August. A wild buckwheat planted in the same bed will still be there in ten years, and it will feed bees in September when little else is open. The genus Eriogonum runs to roughly 250 species, most of them western, and the range of forms is wide: sulfur buckwheat, California buckwheat, Saint Catherine's lace. The field notes on Eriogonum treat the genus species by species, which matters, because the differences between them decide whether a plant survives your summer or not.

What is a wild buckwheat, and how does it differ from the buckwheat grain we eat?

The grain buckwheat, Fagopyrum esculentum, is an annual. It germinates in spring, flowers in six to eight weeks, sets triangular black seeds, and dies at frost. Farmers plant it as a cover crop or a short-season grain. It has nothing to do with the genus Eriogonum, which sits in the Polygonaceae as well but branches off early. Wild buckwheats are perennials, subshrubs or shrubs, and they are adapted to dry summers, lean soil and full sun. Their seed is small and winged, not the starchy kernel milled for pancakes.

A practical test: if the plant survives a western summer with no irrigation and comes back the next year, it is probably a wild buckwheat. If it dies at the first hard frost and has to be replanted from seed, it is the crop.

How do you identify a wild buckwheat on a hike?

Start with the flowers. Eriogonum flowers are tiny, often less than a quarter inch across, and they are packed into dense clusters at the ends of stems. The clusters are the thing you see from the trail: white, cream, yellow, pink or red, held above the foliage. Sulfur buckwheat carries yellow clusters on stems that rise a foot or more above gray leaves. California buckwheat forms flat-topped white to pink clusters on a rounded shrub three to four feet tall. Saint Catherine's lace holds a broad, flat, white head that looks like a lace doily laid over the bush.

Then look at the leaves. Most wild buckwheats have leaves arranged in a basal rosette or clustered at the base of the stems. The leaf surface is usually woolly or hairy, gray-green to silver, and the hairs are what cut water loss in summer heat. Leaves are simple, entire, and often oval to round. If you rub one between your fingers, the felted texture is unmistakable.

The decisive feature is the involucre. In Eriogonum, each flower cluster sits inside a cup of fused bracts, a small structure called an involucre. The involucre has teeth or lobes at its rim, and it holds the flowers. No other common western shrub combines tiny flowers, woolly leaves and a cup of bracts at the base of each cluster. Once you learn to look for the involucre, identification gets much faster. A hand lens helps; the structure is often less than an eighth of an inch wide.

Habitat narrows it further. Wild buckwheats grow in sagebrush steppe, chaparral, pinyon-juniper woodland, desert flats and rocky slopes, usually in open ground with sharp drainage. If you are standing on a dry hillside in the western United States above 2,000 feet, there is a fair chance an Eriogonum is within arm's reach.

Which buckwheat should a small dry garden start with?

For a first planting, choose a species that matches your site rather than the one with the showiest flower. Three are widely grown and forgiving.

Sulfur buckwheat, Eriogonum umbellatum, is the safest starting point for most western gardens. It is a low mat or small subshrub, six to eighteen inches tall, with gray-green leaves and yellow flower heads that age to orange and rust. It takes full sun, needs sharp drainage, and tolerates cold winters. It is also variable across its range, so buy plants grown from seed collected near your elevation if you can.

California buckwheat, Eriogonum fasciculatum, suits low-elevation gardens in California and the Southwest. It grows three to four feet tall and wide, takes heat and reflected light, and flowers from spring into fall. It is a good choice for a slope or a parking strip where nothing else holds.

Saint Catherine's lace, Eriogonum giganteum, is the large one, up to six feet, native to the Channel Islands and coastal southern California. It wants mild winters and no summer water once established. Plant it where its white flower heads can be seen from a window, and give it room.

Whichever you pick, plant in fall, not spring. Fall planting lets roots grow through the cool months before the first dry summer. Set the plant in a hole no deeper than its root ball, backfill with the native soil, and water once. Then water sparingly through the first summer, perhaps every two to three weeks, and stop by the second year. Mulch with gravel, not bark, and keep mulch off the crown. Do not fertilize. Rich soil and regular water make wild buckwheats soft, floppy and short-lived.

What does a wild buckwheat ask of its owner after planting?

Less than most garden shrubs. The main tasks are drainage, restraint with water, and light pruning.

Drainage first. If water stands around the crown for a day after rain, the plant will rot. On heavy soil, plant on a slight mound or in a raised bed with a coarse mineral mix. On clay, add grit to the planting hole and keep the crown above grade.

Water second. Established wild buckwheats in the ground want no summer water in most of the West. In a container, water deeply but let the mix dry between waterings. In the first year, water enough to keep the plant from collapsing, and no more.

Pruning third. Most species stay compact if you shear the spent flower heads back by a third in late winter, before new growth starts. Do not cut into old, leafless wood; wild buckwheats rarely resprout from bare stems. On California buckwheat, a light shaping in late winter keeps the shrub dense. On sulfur buckwheat, deadhead through the season if you want a second flush.

What lives on the flowers?

Late summer is the reason to plant wild buckwheat. When most western natives have finished blooming, Eriogonum flower heads are still open, and they are visited by native bees, honeybees, butterflies and hummingbirds. The nectar is accessible in the shallow flowers, and the seed that follows feeds birds and small mammals into fall. A single sulfur buckwheat in full flower will hold dozens of insects at midday.

That is the argument for putting one in a small yard. It costs one planting hole, one fall afternoon, and a gravel mulch. In return it stays green through the dry months, needs no fertilizer and almost no water, and gives the late-season pollinators something to work.

If you are new to the genus, start with one plant, watch it through a full year, and note what it does in each month. The plant will tell you more about your site than any list can.