Threadleaf Fleabane

Erigeron filifolius

Asteraceae

• Spokane Native
• Sun-Part Shade
• Size: 1’ tall x 1’ wide
• Drought Tolerant: Yes
• Evergreen: no
• Flower Color: White, blue, pink, or pale lavender with yellow centers (May - July)
• Wildlife Value: bees, butterflies, and other pollinators; provides nectar for beneficial insects

Threadleaf Fleabane is a charming low-growing perennial that forms attractive clumps of erect to spreading stems rising 4 to 20 inches tall. This hardy native thrives east of the Cascades in sagebrush plains, dry slopes, and grasslands, making it exceptionally well-suited to xeric gardens and challenging sites. The plant grows from a taproot and short woody base, demonstrating excellent drought tolerance once established. It prefers full sun and well-drained sandy, gravelly, or rocky soils where it naturalizes readily without becoming invasive. The distinctive thread-like foliage is densely covered with fine, appressed hairs that give the plant a soft, silvery appearance.

The delicate daisy-like flowers are borne singly or in clusters atop branching stems, with each flower head measuring about one-third inch across. The blooms feature 15-125 slender ray florets in shades of white, blue, pink, or pale lavender surrounding cheerful yellow disc flowers. Two varieties exist in the region: the common variety filifolius produces numerous flower heads on each stem with 15-75 rays, while the sturdier variety robustior displays solitary flower heads topped with 50-125 rays. The narrow leaves are mostly basal, measuring 1-3 inches long and thread-like in width, with smaller leaves ascending the stems. This fine-textured foliage remains attractive even when not in bloom.

Threadleaf Fleabane provides valuable nectar resources for native bees, butterflies, and other pollinating insects throughout late spring and summer. The abundant flowers support beneficial insect populations that help maintain healthy garden ecosystems. While not heavily documented for ethnobotanical uses, this species plays an important ecological role in native plant communities, providing food and habitat for various insects and contributing to biodiversity. The plant's ability to thrive in harsh, dry conditions makes it a pioneer species that helps stabilize soil and support other native plants.

This low-maintenance perennial excels in rock gardens, at the base of shrubs, on dry slopes, and in wildflower meadows where its delicate flowers and fine-textured foliage add charm without overwhelming neighboring plants. The compact size makes it perfect for small urban gardens, entries, courtyards, and confined spaces. Threadleaf Fleabane pairs beautifully with other drought-tolerant natives including Shaggy Fleabane, Oregon Sunshine, Buckwheats, Yarrow, and native bunchgrasses. It naturalizes gently through self-seeding in suitable conditions, creating drifts of soft color in late spring and early summer. The plant requires virtually no maintenance once established and tolerates poor soils, making it an ideal choice for sustainable, water-wise landscapes in the Spokane region.