Thermopsis gracilis – Slender Thermopsis
 
Native Habitat:
Open forests, grasslands, and rocky slopes.
 
Bloom Time:
May – July
 
Growth Habit & Mature Size:
Perennial herb, 1–3 feet tall, with erect stems and pinnately compound leaves. Produces clusters of bright yellow, pea-like flowers along the upper stems.
 
Light & Soil Requirements:
Full sun; thrives in sandy, loamy, or gravelly soils. Tolerates seasonal dryness once established.
 
Willamette Valley Native Companion Plants:
Camassia quamash, Achillea millefolium, Eriophyllum lanatum, Sidalcea campestris, Festuca idahoensis.
 
Urban Garden Function:
Adds vibrant summer blooms, vertical structure, and pollinator support to urban gardens, naturalized landscapes, and native plantings. Works well in layered plantings, habitat-focused borders, and low-maintenance urban gardens.
 
Wildlife Supported:
Flowers attract native bees, butterflies, and other pollinators. Foliage provides shelter for insects and small invertebrates.
 
Historical Use:
Used ornamentally for its bright yellow flowers and ecological role; valued in native prairie, meadow, and pollinator-friendly garden plantings.