Sulphur Flower Buckwheat

Eriogonum umbellatum

Polygonaceae

• Spokane Native
• Sun-Part Sun
• Size: 6"-18" tall x 12"-3' wide
• Drought Tolerant: Yes
• Evergreen: semi
• Flower Color: yellow, fading to orange/red (May - September)
• Wildlife Value: bees, butterflies, moths, hummingbirds

Sulphur Flower Buckwheat is an extremely variable, mat-forming perennial native to dry, rocky slopes and ridges throughout eastern Washington and the western mountains. This adaptable plant develops woody stems at the base and forms broad, spreading mounds of small, spatula-shaped leaves that are green above and white-felted beneath. Thriving in well-drained to gravelly soils and full sun, it is perfectly suited to Spokane's dry climate and rocky sites. Once established, this drought-tolerant native requires virtually no supplemental water and can even survive in pure gravel, making it ideal for the most challenging xeric conditions.

The brilliant sulfur-yellow flowers emerge from red-tinted buds and bloom prolifically from early summer through fall, held in dense, frilly clusters up to four inches wide atop leafless flowering stalks. The blossoms are spectacular against the gray-green foliage, creating a vibrant display that lasts for months. As flowers mature, they fade to orange and finally to a rusty red-burgundy color that adds autumn interest and can be harvested for dried arrangements. The foliage itself provides year-round appeal, turning attractive red-russet tones in winter before greening up again in spring.

Sulphur Flower Buckwheat is an ecological powerhouse, serving as a critical larval host plant for numerous butterfly species including the Mormon Metalmark, Rocky Mountain Dotted Blue, Lupine Blue, Desert Green Hairstreak, and Sheridan's Hairstreak. The flowers attract bees, hover flies, butterflies, moths, and hummingbirds with abundant nectar throughout the long blooming season, while the seeds provide valuable food for birds and small mammals. Native American tribes including the Kawaiisu, Paiute, Shoshoni, Blackfoot, and Navajo traditionally used various parts of the plant for medicinal purposes, treating everything from stomach ailments to skin conditions, and the Blackfoot made tea from the leaves.

This versatile groundcover excels in rock gardens, xeriscapes, slope stabilization, and as a flowering groundcover where little else will grow. Plant it in hot, exposed sites with poor, rocky soil where its low-maintenance nature truly shines. Sulphur Flower Buckwheat pairs beautifully with other dry-site natives including sagebrush (Artemisia species), rabbitbrush (Ericameria nauseosa), purple sage (Salvia dorrii), Penstemon species, and native grasses. Its spreading habit makes it excellent for erosion control on banks and slopes, while its long bloom season provides continuous color when many other plants have finished flowering. Shear back spent flower stalks in late fall or leave them for winter interest and wildlife value.