Our native Sulphur Buckwheat that is among the best for general garden culture in our climate. This ubiquitous creeping plant of alpine areas of Oregon celebrates spring with umbels of (sulphur) yellow flowers on long stalks. The low and spreading rosette of leaves are thick green on top with silver indumentum on the reverse. Full sun in fast draining conditions- ideally rock garden conditions because that is where you find it. Crevasses between rocks is where it lives. This is easily reenacted in your garden at the top of a porous rock wall. Blooms May-July for an extended time. The flowers go through a fascinating metamorphosis in color as they open, reach their peak of hot yellow and then turn to russet/red seed heads. These abandon the spike through autumn and spent flower spikes may be removed in winter. Water until you see the rosettes actively increasing. Then taper to once in a while. This species has a total of 13 (!) subspecies in Oregon alone. We have yet to delve into specific subspecies but if we did I would look for Eriogonum umbellatum var. modocensis and Eriogonum umbellatum var. umbellatum. Both are endemic to Mary’s Peak the tallest point in the Coast Range (4097′). So, I know that those (with immaculate drainage) can easily cope with higher rainfall. Rock garden staple and can also self sow in happy places. Very fun, sunny, satisfying native to grow. Associated plants in habitat are Prunella vulgaris var. lanceolata and Achillea millefolium, Sedum oreganum, Castilleja minuta and Penstemon cardwelii. Excellently adapted to gravel, crevice, gardens with an arid aesthetic. Amend the soil as for Agaves and it will thrive. Pronounced Air-e-OG-oh-num. Rosettes to 3″ tall, blooming stems to 1′ tall. Spreads, give it room. Oregon native plant.
Eriogonum umbellatum
Family: Polygonaceae Genus: Eriogonum
Plant type: Herbaceous perennial
Biomes/Growing conditions: Hot Aspects, Low Water/No Water, Western Native, Willamette Valley Natives
Sun exposure: Full Sun
USDA Hardiness zone: Zn5a -15º to -20ºF
Foliage color: Silver/Gray
Foliage season: Evergreen